Sad to see that no one has replied to this sooner.
Your Server Task Log should include records for Repoistory Pull tasks. Dates, times and the content that you downloaded.
The best way to show DAT version compliance-over-time would be to setup Compliance Events. In short, create a compliance query the displays red/green how many systems are within X number of DAT versions. Then create a Server Task with two steps: one to periodically run the query; and another to create a compliance event with the results. Lastly, build a seconds query that displays those compliance events over the time period in question.
Note: This compliance data will only help you moving forward. Sadly, ePO can't travel back in time to revel in the glory of how things once were.
moved to epo group.