Running total on a filtered table

I have a table with revenues and expenses that is filtered by a slicer using Forecast ID. I'm trying to get a running total (Forecast Cumulative), but I can't seem to get the measure right. Here's what my table looks like. Forecast Cumulative is the measure:

The measure is: 

Forecast Cumulative = calculate(sum('Forecast Date Revenue Expense'[Revenue])-sum('Forecast Date Revenue Expense'[Expense]))

As you can see, it is just subtracting the expense from the revenue for each row. I need it to generate a running total so Forecast Cumulative should be:

15195

20204

11679

4530

etc

I'm sure I have the filters wrong, but not sure how to fix it.

Thanks!