@Evers, this can be performed internally in your organization, but is a more involved and lengthy process that requires the knowledge and utilization around the Agile Central Web Services API and Lookback API documentation, both of which I have linked to below:
Web Services API: https://rally1.rallydev.com/slm/doc/webservice/ (requires you to be logged into your Agile Central account)
Lookback API: https://rally1.rallydev.com/analytics/doc/ (requires you to be logged into your Agile Central account)
If you would prefer to not leverage internal resources for this, the quickest way to get this data is by requesting this type of full subscription dump from Support.