GarageSale Reports function - "Profit"

I use the Reports function of GarageSale to produce a sales report for my
Tax consultant.
I select the following fields for each sold item:

Final Price
Final Value Fee
Listing Fees
Item Cost
and
Profit

In my simple mind the “Profit” figure should be
Final Price - Final Value Fee - Item Cost

(I have no “listing fees” as I am an eBay Store owner)
In the Report, the above calculations do not work - ”profit” shows as a figure I do not understand.

Does anybody know how the “Profit” figure in Reports is calculated please?

Many thanks
David James