cumulative pivot graph

[rinogjb]

I have 2 projects with estimated and actual cost. entries for each Month. I have a pivot chart but would like it to be cumulative sum month to month. instead of sum of each month.
Is there an easy way to do this without adding columns and manipulating the data?

 

[rinogjb]

Found it: Using value field setting and showing values as a running total by month.