Reverse Running Total

Hi all,

I am trying to create a 'reverse running total' as it were, where the first year shows the grand total, and then with each year it decreases down to 0.
Is this possible in a pivot table, without adding an additional helper column in the source data?

Cheers!

You'd have to make a SUM cell, put it at the top row in a new column,
Then subtract each row as you go down the rows.

Thanks for the suggestion - not quite what I was looking for in terms of doing it in the pivot.
I ideally want to do it without adding an extra column in the source the pivot comes from (as this comes from an external source, and we had hoped to keep it clean with no additional formulae - if this is not possible I know other ways of doing it, just wanted to see if anyone knew of a clever pivot method!)