Getting Pivot Table to give monthly Average

For a pivot table with row labels of Catagory and Date and Sum of Values in Values,

I Group dates by Month and have the pivot table show Sum of values per month. I'd like to have it give a monthly average each month for each catagory instead of Sumtotal. Is there an easy way to do that?

Have you tried setting the field value to Average rather than Sum?

It would probably be easier to understand if you could post example.
Create a example data set to illustrate current pt construction.

The Average setting gives average transaction so that doesn't work. Here's an example.

Does this give you the information you want?

Table has Sum, Count and Average in it.

Sorry Andy, I updated with a better example, must have been while you were looking at the old example. So for Catagory A, the monthly average would be 78.2.

Thanks Marvin,
That's what I was afraid of. Seems like it would be a nice feature to have built in since they do have that option with the FUNCTION Subtotal. Oh well.