Using Count to calculate average over time

I have a table listing Users (UserID) and Groups (GroupID). I can run a count to find how many Groups each user belong to i.e. Count, group by UserID. I then want to calculate the average and also the average over time to see how the average group size is increasing/decreasing over time. Any ideas how I could achieve this? Thanks

Hi @gerthomas
Perhaps I don't fully understand what you're trying to do, but something like this? Otherwise you might need to do it in SQL, but could you show how you expect the result to look like with?