I have a database with weekly sales per store/sku and my reports are grouped by month and year. I was able to sum sales in rolling years (last 52 weeks or last 12 months), as you can see below. Now I would like to include Sales Variation, but not considering monthly sales. I would like to compare the Last Rolling Year to Previous Rolling Year (in this case July16 vs July15). Does anyone know how to do this?
I have another sheet where I will input only the rolling years variation (in the case mentioned above, as my history is being populated, the variation will be available for upcoming months). I believe the calculation is similar, but I would need to report less periods.