I am trying to create a cross table that has year over year percentage differences by month.

I am trying to create a cross table that has year over year percentage differences by month. For months that are already complete (i.e. it's mid-March as I write this, so for Jan and Feb), my expression seems to work well. But for the current month, it is comparing my half-complete March against my fully-complete March from last year. Is there a way to tweak my formula so that it still works for completed months but for the current month will compare the first, say, 18 days of this month against the first 18 days of the month last year? 

Here's what I have so far:

Sum([FCT_UNIT_QTY]) - Sum([FCT_UNIT_QTY]) OVER (ParallelPeriod([Axis.Columns]))) / Sum([FCT_UNIT_QTY]) OVER (ParallelPeriod([Axis.Columns])) as [Diff%]

(2) Answers

Login