This year/ Last Year comparison - Over different periods

[#1]

HI all,

I am having an issue with This Year/Last Year comparison of sales.  Usually if we are getting the Last Year figure for year on year our set analysis would just be "SUM({$<year={$(#=Only(year)-1)}>} [sales-value] - [Disc amount])" which works fine but because I am rolling across years (week 50, 2015 - week4, 2016 see image below) the formula does not work for the Last Year figure as it previously did.  I have tried alternatives but to no avail and was wondering if anyone can think of how I can fix this? Any help on this would be greatly appreciated.

Thanks,

Brian

[-SW-]

Hi Brian,

Would you be able to provide sample app to look into this with greater detail?

Thanks,

Shun