diff --git a/CHANGELOG.md b/CHANGELOG.md
index 484daed35..e09837164 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # Changelog Fab-manager
 
+- Fix a bug: unable to export statistics
 - Fix a bug: soft destroyed machines and spaces are still reported in the OpenAPI
 
 ## v5.5.5 2022 November 22
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 60ef47237..92f888aaa 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -47,7 +47,7 @@ module ApplicationHelper
     message = MessageFormat.new(I18n.t(scope_key_by_partial(key)), I18n.locale.to_s)
     text = message.format(interpolations)
     if html_safe_translation_key?(key)
-      text.html_safe
+      text.html_safe # rubocop:disable Rails/OutputSafety
     else
       text
     end
@@ -65,23 +65,6 @@ module ApplicationHelper
     amount / 100.00
   end
 
-  ##
-  # Retrieve an item in the given array of items
-  # by default, the "id" is expected to match the given parameter but
-  # this can be overridden by passing a third parameter to specify the
-  # property to match
-  ##
-  def get_item(array, id, key = nil)
-    array.each do |i|
-      if key.nil?
-        return i if i.id == id
-      elsif i[key] == id
-        return i
-      end
-    end
-    nil
-  end
-
   ##
   # Apply a correction for a future DateTime due to change in Daylight Saving Time (DST) period
   # @param reference {ActiveSupport::TimeWithZone}
@@ -98,6 +81,7 @@ module ApplicationHelper
   private
 
   ## inspired by gems/actionview-4.2.5/lib/action_view/helpers/translation_helper.rb
+  # rubocop:disable Rails/HelperInstanceVariable
   def scope_key_by_partial(key)
     if key.to_s.first == '.'
       raise "Cannot use t(#{key.inspect}) shortcut because path is not available" unless @virtual_path
@@ -107,6 +91,7 @@ module ApplicationHelper
       key
     end
   end
+  # rubocop:enable Rails/HelperInstanceVariable
 
   def html_safe_translation_key?(key)
     key.to_s =~ /(\b|_|\.)html$/
diff --git a/app/helpers/excel_helper.rb b/app/helpers/excel_helper.rb
new file mode 100644
index 000000000..81653b6d2
--- /dev/null
+++ b/app/helpers/excel_helper.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+# Helpers for excel exports, for use with AXSLX gem
+module ExcelHelper
+  # format the given source data for an Excell cell
+  def format_xlsx_cell(source_data, data, styles, types, date_format: nil, source_data_type: '')
+    case source_data_type
+    when 'date'
+      data.push Date.strptime(source_data, '%Y-%m-%d')
+      styles.push date_format
+      types.push :date
+    when 'list'
+      data.push source_data.map { |e| e['name'] }.join(', ')
+      styles.push nil
+      types.push :string
+    when 'number'
+      data.push source_data
+      styles.push nil
+      types.push :float
+    else
+      data.push source_data
+      styles.push nil
+      types.push :string
+    end
+  end
+
+  # build a new excel line for a statistic export
+  def statistics_line(hit, user, type, subtype, date_format)
+    data = [
+      Date.strptime(hit['_source']['date'], '%Y-%m-%d'),
+      user&.profile&.full_name || t('export.deleted_user'),
+      user&.email || '',
+      user&.profile&.phone || '',
+      t("export.#{hit['_source']['gender']}"),
+      hit['_source']['age'],
+      subtype.nil? ? '' : subtype.label
+    ]
+    styles = [date_format, nil, nil, nil, nil, nil, nil]
+    types = %i[date string string string string integer string]
+    # do not proceed with the 'stat' field if the type is declared as 'simple'
+    unless type.simple
+      data.push hit['_source']['stat']
+      styles.push nil
+      types.push :string
+    end
+
+    [data, styles, types]
+  end
+
+  # append a cell containing the CA amount
+  def add_ca_cell(index, hit, data, styles, types)
+    return unless index.ca
+
+    data.push hit['_source']['ca']
+    styles.push nil
+    types.push :float
+  end
+
+  ##
+  # Retrieve an item in the given array of items
+  # by default, the "id" is expected to match the given parameter but
+  # this can be overridden by passing a third parameter to specify the
+  # property to match
+  ##
+  def get_item(array, id, key = nil)
+    array.each do |i|
+      if key.nil?
+        return i if i.id == id
+      elsif i[key] == id
+        return i
+      end
+    end
+    nil
+  end
+end
diff --git a/app/services/export_service.rb b/app/services/export_service.rb
index a77d07c57..51e826a97 100644
--- a/app/services/export_service.rb
+++ b/app/services/export_service.rb
@@ -27,9 +27,9 @@ class ExportService
 
     def query_last_export(category, export_type, query = nil, key = nil, extension = nil)
       export = Export.where(category: category, export_type: export_type)
-      export.where(query: query) unless query.nil?
-      export.where(key: key) unless key.nil?
-      export.where(extension: extension) unless extension.nil?
+      export = export.where(query: query) unless query.nil?
+      export = export.where(key: key) unless key.nil?
+      export = export.where(extension: extension) unless extension.nil?
       export
     end
 
diff --git a/app/services/statistics/builders/reservations_builder_service.rb b/app/services/statistics/builders/reservations_builder_service.rb
index 57a1d7a3a..6c6bea826 100644
--- a/app/services/statistics/builders/reservations_builder_service.rb
+++ b/app/services/statistics/builders/reservations_builder_service.rb
@@ -21,16 +21,34 @@ class Statistics::Builders::ReservationsBuilderService
             stat[:stat] = (type == 'booking' ? 1 : r[:nb_hours])
             stat["#{category}Id".to_sym] = r["#{category}_id".to_sym]
 
-            if category == 'event'
-              stat[:eventDate] = r[:event_date]
-              stat[:eventTheme] = r[:event_theme]
-              stat[:ageRange] = r[:age_range]
-            end
-
+            stat = add_custom_attributes(category, stat, r)
             stat.save
           end
         end
       end
     end
+
+    def add_custom_attributes(category, stat, reservation_data)
+      stat = add_event_attributes(category, stat, reservation_data)
+      add_training_attributes(category, stat, reservation_data)
+    end
+
+    def add_event_attributes(category, stat, reservation_data)
+      return stat unless category == 'event'
+
+      stat[:eventDate] = reservation_data[:event_date]
+      stat[:eventTheme] = reservation_data[:event_theme]
+      stat[:ageRange] = reservation_data[:age_range]
+
+      stat
+    end
+
+    def add_training_attributes(category, stat, reservation_data)
+      return stat unless category == 'training'
+
+      stat[:trainingDate] = reservation_data[:training_date]
+
+      stat
+    end
   end
 end
diff --git a/app/services/statistics_export_service.rb b/app/services/statistics_export_service.rb
index 43422b664..06aeeb21d 100644
--- a/app/services/statistics_export_service.rb
+++ b/app/services/statistics_export_service.rb
@@ -6,12 +6,11 @@ require 'action_view'
 require 'active_record'
 
 # require any helpers
-require './app/helpers/application_helper'
+require './app/helpers/excel_helper'
 
+# Export statistics (from elasticsearch) to an excel file
 class StatisticsExportService
-
   def export_global(export)
-
     # query all stats with range arguments
     query = MultiJson.load(export.query)
 
@@ -30,18 +29,19 @@ class StatisticsExportService
 
     ActionController::Base.prepend_view_path './app/views/'
     # place data in view_assigns
-    view_assigns = {results: @results, users: @users, indices: @indices}
+    view_assigns = { results: @results, users: @users, indices: @indices }
     av = ActionView::Base.new(ActionController::Base.view_paths, view_assigns)
     av.class_eval do
       # include any needed helpers (for the view)
-      include ApplicationHelper
+      include ExcelHelper
     end
 
     content = av.render template: 'exports/statistics_global.xlsx.axlsx'
     # write content to file
-    File.open(export.file, 'w+b') { |f| f.write content }
+    File.binwrite(export.file, content)
   end
 
+  # rubocop:disable Style/DocumentDynamicEvalDefinition
   %w[account event machine project subscription training space].each do |path|
     class_eval %{
       def export_#{path}(export)
@@ -71,14 +71,14 @@ class StatisticsExportService
         av = ActionView::Base.new(ActionController::Base.view_paths, view_assigns)
         av.class_eval do
           # include any needed helpers (for the view)
-          include ApplicationHelper
+          include ExcelHelper
         end
 
         content = av.render template: 'exports/statistics_current.xlsx.axlsx'
         # write content to file
-        File.open(export.file,"w+b") { |f| f.write content }
+        File.binwrite(export.file, content)
       end
     }, __FILE__, __LINE__ - 35
   end
-
+  # rubocop:enable Style/DocumentDynamicEvalDefinition
 end
diff --git a/app/views/exports/statistics_current.xlsx.axlsx b/app/views/exports/statistics_current.xlsx.axlsx
index 76c676854..e4b8062c4 100644
--- a/app/views/exports/statistics_current.xlsx.axlsx
+++ b/app/views/exports/statistics_current.xlsx.axlsx
@@ -1,79 +1,46 @@
+# frozen_string_literal: true
+
 wb = xlsx_package.workbook
 
-bold = wb.styles.add_style :b => true
-header = wb.styles.add_style :b => true, :bg_color => Stylesheet.primary.upcase.gsub('#', 'FF'), :fg_color => 'FFFFFFFF'
-date = wb.styles.add_style :format_code => Rails.application.secrets.excel_date_format
+bold = wb.styles.add_style b: true
+header = wb.styles.add_style b: true, bg_color: Stylesheet.primary.upcase.gsub('#', 'FF'), fg_color: 'FFFFFFFF'
+date = wb.styles.add_style format_code: Rails.application.secrets.excel_date_format
 
 wb.add_worksheet(name: @index.label) do |sheet|
   ## heading stats for the current page
-  sheet.add_row [t('export.entries'), @results['hits']['total']], :style => [bold, nil], :types => [:string, :integer]
+  sheet.add_row [t('export.entries'), @results['hits']['total']], style: [bold, nil], types: %i[string integer]
   if @index.ca
-    sheet.add_row [t('export.revenue'), @results['aggregations']['total_ca']['value']], :style => [bold, nil], :types => [:string, :float]
+    sheet.add_row [t('export.revenue'), @results['aggregations']['total_ca']['value']], style: [bold, nil], types: %i[string float]
   end
-  sheet.add_row [t('export.average_age'), @results['aggregations']['average_age']['value']], :style => [bold, nil], :types => [:string, :float]
+  sheet.add_row [t('export.average_age'), @results['aggregations']['average_age']['value']], style: [bold, nil], types: %i[string float]
   unless @type.simple
-    sheet.add_row ["#{t('export.total')} #{@type.label}", @results['aggregations']['total_stat']['value']], :style => [bold, nil], :types => [:string, :integer]
+    sheet.add_row ["#{t('export.total')} #{@type.label}", @results['aggregations']['total_stat']['value']],
+                  style: [bold, nil],
+                  types: %i[string integer]
   end
   sheet.add_row []
 
   ## data table
   # heading labels
-  columns = [t('export.date'), t('export.user'), t('export.email'), t('export.phone'), t('export.gender'), t('export.age'), t('export.type')]
+  columns = [t('export.date'), t('export.user'), t('export.email'), t('export.phone'), t('export.gender'), t('export.age'),
+             t('export.type')]
   columns.push @type.label unless @type.simple
   @fields.each do |f|
     columns.push f.label
   end
   columns.push t('export.revenue') if @index.ca
-  sheet.add_row columns, :style => header
+  sheet.add_row columns, style: header
 
   # data rows
   @results['hits']['hits'].each do |hit|
     user = get_item(@users, hit['_source']['userId'])
     subtype = get_item(@subtypes, hit['_source']['subType'], 'key')
-    data = [
-        Date::strptime(hit['_source']['date'],'%Y-%m-%d'),
-        (user ? user.profile.full_name : "ID #{hit['_source']['userId']}"),
-        (user ? user.email : ''),
-        (user ? user.profile.phone : ''),
-        t("export.#{hit['_source']['gender']}"),
-        hit['_source']['age'],
-        subtype.nil? ? "" : subtype.label
-    ]
-    styles = [date, nil, nil, nil, nil, nil, nil]
-    types = [:date, :string, :string, :string, :string, :integer, :string]
-    unless @type.simple
-      data.push hit['_source']['stat']
-      styles.push nil
-      types.push :string
-    end
+    data, styles, types = statistics_line(hit, user, @type, subtype, date)
     @fields.each do |f|
-      field_data = hit['_source'][f.key]
-      case f.data_type
-        when 'date'
-          data.push Date::strptime(field_data, '%Y-%m-%d')
-          styles.push date
-          types.push :date
-        when 'list'
-          data.push field_data.map{|e| e['name'] }.join(', ')
-          styles.push nil
-          types.push :string
-        when 'number'
-          data.push field_data
-          styles.push nil
-          types.push :float
-        else
-          data.push field_data
-          styles.push nil
-          types.push :string
-      end
-
-    end
-    if @index.ca
-      data.push hit['_source']['ca']
-      styles.push nil
-      types.push :float
+      format_xlsx_cell(hit['_source'][f.key], data, styles, types, source_data_type: f.data_type, date_format: date)
     end
+    add_ca_cell(@index, hit, data, styles, types)
 
-    sheet.add_row data, :style =>  styles, :types => types
+    sheet.add_row data, style: styles, types: types
   end
-end
\ No newline at end of file
+end
diff --git a/app/views/exports/statistics_global.xlsx.axlsx b/app/views/exports/statistics_global.xlsx.axlsx
index f2953ff66..2b9a723d5 100644
--- a/app/views/exports/statistics_global.xlsx.axlsx
+++ b/app/views/exports/statistics_global.xlsx.axlsx
@@ -1,84 +1,48 @@
+# frozen_string_literal: true
+
 wb = xlsx_package.workbook
 
-header = wb.styles.add_style :b => true, :bg_color => Stylesheet.primary.upcase.gsub('#', 'FF'), :fg_color => 'FFFFFFFF'
-date = wb.styles.add_style :format_code => Rails.application.secrets.excel_date_format
+header = wb.styles.add_style b: true, bg_color: Stylesheet.primary.upcase.gsub('#', 'FF'), fg_color: 'FFFFFFFF'
+date = wb.styles.add_style format_code: Rails.application.secrets.excel_date_format
 
 @indices.each do |index|
-  if index.table
-    index.statistic_types.each do |type|
-      # see https://msdn.microsoft.com/fr-fr/library/c6bdca6y(v=vs.90).aspx for unauthorized character list
-      sheet_name = "#{index.label} - #{type.label}".gsub(/[*|\\:"<>?\/]/,'').truncate(31)
-      wb.add_worksheet(name: sheet_name) do |sheet|
+  next unless index.table
 
-        ## data table
-        # heading labels
-        columns = [t('export.date'), t('export.user'), t('export.email'), t('export.phone'), t('export.gender'), t('export.age'), t('export.type')]
-        columns.push type.label unless type.simple
+  index.statistic_types.each do |type|
+    # see https://msdn.microsoft.com/fr-fr/library/c6bdca6y(v=vs.90).aspx for unauthorized character list
+    sheet_name = "#{index.label} - #{type.label}".gsub(%r{[*|\\:"<>?/]}, '').truncate(31)
+    wb.add_worksheet(name: sheet_name) do |sheet|
+      ## data table
+      # heading labels
+      columns = [t('export.date'), t('export.user'), t('export.email'), t('export.phone'), t('export.gender'), t('export.age'),
+                 t('export.type')]
+      columns.push type.label unless type.simple
+      index.statistic_fields.each do |f|
+        columns.push f.label
+      end
+      columns.push t('export.revenue') if index.ca
+      sheet.add_row columns, style: header
+
+      # data rows
+      @results['hits']['hits'].each do |hit|
+        # check that the current result is for the given index and type
+        next unless hit['_type'] == index.es_type_key && hit['_source']['type'] == type.key
+
+        # get matching objects
+        user = get_item(@users, hit['_source']['userId'])
+        subtype = get_item(type.statistic_sub_types, hit['_source']['subType'], 'key')
+        # start to fill data and associated styles and data-types
+        data, styles, types = statistics_line(hit, user, type, subtype, date)
+        # proceed additional fields
         index.statistic_fields.each do |f|
-          columns.push f.label
+          format_xlsx_cell(hit['_source'][f.key], data, styles, types, source_data_type: f.data_type, date_format: date)
         end
-        columns.push t('export.revenue') if index.ca
-        sheet.add_row columns, :style => header
+        # proceed the 'ca' field if requested
+        add_ca_cell(index, hit, data, styles, types)
 
-        # data rows
-        @results['hits']['hits'].each do |hit|
-          # check that the current result is for the given index and type
-          if hit['_type'] == index.es_type_key and hit['_source']['type'] == type.key
-            # get matching objects
-            user = get_item(@users, hit['_source']['userId'])
-            subtype = get_item(type.statistic_sub_types, hit['_source']['subType'], 'key')
-            # start to fill data and associated styles and data-types
-            data = [
-                Date::strptime(hit['_source']['date'],'%Y-%m-%d'),
-                (user ? user.profile.full_name : "ID #{hit['_source']['userId']}"),
-                (user ? user.email : ''),
-                (user ? user.profile.phone : ''),
-                t("export.#{hit['_source']['gender']}"),
-                hit['_source']['age'],
-                subtype.nil? ? "" : subtype.label
-            ]
-            styles = [date, nil, nil, nil, nil, nil, nil]
-            types = [:date, :string, :string, :string, :string, :integer, :string]
-            # do not proceed with the 'stat' field if the type is declared as 'simple'
-            unless type.simple
-              data.push hit['_source']['stat']
-              styles.push nil
-              types.push :string
-            end
-            # proceed additional fields
-            index.statistic_fields.each do |f|
-              field_data = hit['_source'][f.key]
-              case f.data_type
-                when 'date'
-                  data.push Date::strptime(field_data, '%Y-%m-%d')
-                  styles.push date
-                  types.push :date
-                when 'list'
-                  data.push field_data.map{|e| e['name'] }.join(', ')
-                  styles.push nil
-                  types.push :string
-                when 'number'
-                  data.push field_data
-                  styles.push nil
-                  types.push :float
-                else
-                  data.push field_data
-                  styles.push nil
-                  types.push :string
-              end
-
-            end
-            # proceed the 'ca' field if requested
-            if index.ca
-              data.push hit['_source']['ca']
-              styles.push nil
-              types.push :float
-            end
-            # finally, add the data row to the workbook's sheet
-            sheet.add_row data, :style =>  styles, :types => types
-          end
-        end
+        # finally, add the data row to the workbook's sheet
+        sheet.add_row data, style: styles, types: types
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 18f76841f..5dcc9c76f 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -474,6 +474,7 @@ en:
     type: "Type"
     male: "Man"
     female: "Woman"
+    deleted_user: "Deleted user"
   #initial price's category for events, created to replace the old "reduced amount" property
   price_category:
     reduced_fare: "Reduced fare"
diff --git a/doc/postgresql_readme.md b/doc/postgresql_readme.md
index 36a1087dc..8de0d458e 100644
--- a/doc/postgresql_readme.md
+++ b/doc/postgresql_readme.md
@@ -19,8 +19,8 @@ cd /apps/fabmanager/
 docker-compose exec postgres bash
 cd /var/lib/postgresql/data/
 DB=$(psql -U postgres -c \\l | grep production | awk '{print $1}')
-pg_dump -U postgres "$DB" > "$DB_$(date -I).sql"
-tar cvzf "fabmanager_database_dump_$(date -I).tar.gz" "$DB_$(date -I).sql"
+pg_dump -U postgres "$DB" > "${DB}_$(date -I).sql"
+tar cvzf "fabmanager_database_dump_$(date -I).tar.gz" "${DB}_$(date -I).sql"
 ```
 
 If you're connected to your server thought SSH, you can download the resulting dump file using the following:
@@ -30,14 +30,15 @@ scp root@remote.server.fab:/apps/fabmanager/postgresql/fabmanager_database_dump_
 
 Restore the dump with the following:
 ```bash
+DUMP=$(tar -tvf "fabmanager_database_dump_$(date -I).tar.gz" | awk '{print $6}')
 tar xvf fabmanager_database_dump_$(date -I).tar.gz
-sudo cp fabmanager_production_$(date -I).sql /apps/fabmanager/postgresql/
+sudo cp "$DUMP" /apps/fabmanager/postgresql/
 cd /apps/fabmanager/
 docker-compose down
 docker-compose up -d postgres
 docker-compose exec postgres dropdb -U postgres fabmanager_production
 docker-compose exec postgres createdb -U postgres fabmanager_production
-docker-compose exec postgres psql -U postgres -d fabmanager_production -f /var/lib/postgresql/data/fabmanager_production_$(date -I).sql
+docker-compose exec postgres psql -U postgres -d fabmanager_production -f "/var/lib/postgresql/data/${DUMP}"
 docker-compose up -d
 ```