I have a rather large pivot table that shows distributors and YTD sales. I need to compare current YTD to last years YTD for the same amount of weeks. An example would be: According to their calendar they just finished week 21. When you create a pivot table it brings all of the data from week 2015. I need a chart that will only compare the first 21 weeks of 2015 to the current 21 weeks. Also, I need it to be able to automatically update with the next week... so when we complete week 22 it will pick up last years data for week 22.

I am not sure if this is even doable. I have looked everywhere online and cannot seem to find any assistance. There are other calculations regarding the quantity of distributors that so far I have been able to figure out.

If this is doable, than I can attach a file.

Please Help!