Pivot Table Calculation

[ambernorris2000]

Thank you ahead of time. Can someone please help me with the steps needed to calculate the difference between two columns that I have showing as "% of parent row total" in a pivot table. The insert calculated field function does not lend to this.

[#2]

@ambernorris2000  I enjoy working with Pivot tables but I have also found a number of the Calculate As functions to be impossible to get working. 

I was trying to use the Difference From calculation but it is not clear what difference I would or should get if I select a Base Field and a Base Value. 

Can anyone shed any light on this?