Purpose

You've enabled the Viewing Site Statistics to track global, space, and site activity and you'd like to preserve or restore them. 

Note that this feature will be removed in Confluence 8.0. For more information, see  CONFSERVER-57612 - Getting issue details... STATUS

Solution

The usage data is stored in its own Lucene index which is located in <confluence-home>/index/plugin/usage. To restore the data you'll need a copy of it, e.g. from a backup or a production instance:

1. Stop Confluence
2. Copy the <confluence-home>/index/plugin/usage from the backup to the production instance
   1. If you're copying from a production instance, ensure that instance is stopped as well
3. Go to  > General Config > Content Indexing > Rebuild

You should now be able to see the restored site statistics