I have two tables that track sales seasonality as well as sales per person per month:
What I'd like to do is divide the sum of all months that have sales values (Jan$ - Feb$, for example) by the sum of the seasonality values through that month (Jan% - Feb%). Specifically, I'd like the sum of the seasonality to be limited, such that it won't divide by the March seasonality number unless the March sales number has a number value (including a zero, but not a blank cell). I'd like to do this per row so that I can calculate per-salesperson seasonality.
Any thoughts on how to tackle this?