I have two tables that track sales seasonality as well as sales per person per month:
Seasonality:
| Seasonality | Jan% | Feb % | Mar% |
|---|---|---|---|
| 4.5% | 6.0% | 7.5% |
Sales:
| Salesperson | Jan$ | Feb$ | Mar$ |
|---|---|---|---|
| John | $1000 | $1200 | |
| Jen | $1350 | $800 |
What I'd like to do is divide the sum of all months that have sales values (Jan$ - 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?