I have a much larger table similar to below. I am not sure really how to describe it other than provide an example of what I am trying to graph. I am having trouble with the calculations and not sure how hard this is to do in Tableau and looking for help...so here it goes:
Total Count of Blue in Jan was 77 (50+22)
Total Count of Blue in Feb was 50 (40+10)
Total percentage difference is -35% (50-77)/77*100
What I want to show in a time series type graph:
For each name (in this case Gelato) Percentage Difference of Gelato's performance against the Total Blue sold so Feb data point would be 15% ( -20% - (-35%)) . The twenty percent comes from Percentage difference on Blue Gelato's performance (40-50)/50*100=-20% and the -35% is the percentage difference of all Blue from Feb to Jan.
This probably went unanswered because you didn't include a package workbook. If you're still looking for an answer for this, post a packaged workbook so we can have something to work with.