I'm trying to get Tableau to calculate and eventually visualize our attrition rate, but I can not seem to get the right formula combinations. Essentially our attrition calc is "terms for past 12 months/avg HC for past 12 months". I can get the window average to calculate the avg HC, but it breaks down when I one of our "companies" into the sheet. It can calculate down, and as a whole, but not when I want to graph out four segments. I assume I'll have the same issue summing the last 12 months of terms as well.