I'm building a report to track mix shift in each month across multiple years. But I'm having trouble make it to work. see the attached the image for what i'd like to present. The category data is not always dichotomous, so i'd like to maintain it in a pivot chart. I don't want to see the absolute sold count, instead, i'd like to see the mix shift in each year/month by category. I've tried multiple ways like show value as % of parent total, etc., and can't figure it out.
here is the expected result.