Different calculations for subtotal row in a visualization

[jjones66]

My subtotals are not giving the me the right information. I have columns for leads, applications and cost, which should be sums of the column, but I also have columns for lead-app ratio and cost per lead and cost per app.  Those should be calculated by dividing the subtotal rows. For example, lead-app ratio should be subtotal of leads / subtotal of application. How do I do this?