Here is a Challenge for the Pros!? Wrong %Total in Pivot, any clever idea?

HERE IS A CHALLENGE !!!

I need to buid a pivot with % (showing the leftover or usage of something).

All in all that's ok, however, when it comes to the "totals" the pivot is taking the SUM % of the sub %, instead of actually calculating the % figures shown in the total again... (sorry but I could not express myself better)

I have treid using a calcualted field... where in one part of the pivot this works perfect, in the other not at all... for some reason that looks even worse than the workaround I did try... (I created a column that calculates the % and then added it like that, but that is still not accurate, in what I'm trying to demonstrate.)

Has anyone got a clever idea on how I could get excel to do my bidding, using a trick or a workaround (adding more columns in the data etc...)?

I have attached the file to show what I mean...
MyProblem.xlsx
(not to mention that I'm having to use German excel here... does not make life simpler but it's fine)