I could be more specific if I had an actual workbook to try out things.
But the first thing I would try is in the YOY growth calc itself, I would wrap the whole thing in another IF layer that did something like this:
IF [whatever date field you are using] < (whatever date range you want this to stop at) THEN
... do your stuff
That approach should leave nulls beyond your limit. (Not specifying an ELSE will result in a null when the implied else condition is hit.)
Thanks, Joe Oppelt You're always among the first to help when I need it, and I appreciate it.
I couldn't quite get there with your suggestion for modifying my calc, but I found a two-step solution.
There may be a more elegant way, but it works.
Posted for those who might find this thread later:
IF ISNULL([Historic data])=TRUE
IF sum([Step 1])>0
THEN [Historic data YoY growth]