(Note to self: Workbook is 9.2)
Not really sure what you mean by "repeat every other year".
What I did here was made a copy of the data source, and in the copy I made a calc to modify the year by adding 2. Then I joined the copy by Registrant and by the hacked year value. This will hook the copy to the original by Registrant, and for each row in the data source, look at the same row two years ago (if any). It's a trick for offsetting dates to look at some prior-year analysis.
I don't know if that's really what you are looking to do, but if it is, that's how you can compare this year to two years ago.
summit_repeats_ 2.twbx 54.4 KB