Pivot Table: Calculated Rows

[benjamin_schulz]

Hi everyone,

i have some trouble with pivot tables.
I have already a pivot table where I show some values.
Now I want to have a second table where I show the relative difference to the selected reference (image below).

I already have a solution but I'm not happy with that. 

thats my try but it doesnt work.

=(Avg({<'$(dimension_selection)'={'$(reference_picker)'}>}Accuracy)-Avg(Accuracy))/Avg({<'$(dimension_selection)'={'$(reference_picker)'}>}Accuracy)

my working solution is based on sorting and "Top()" function. I sort the reference on top of the pivot table and have

=(-Top(Avg(Accuracy))+Avg(Accuracy))/Top(Avg(Accuracy))

 as measure. But I want the reference sorted logically. 

thats working, but not how I want it to be.

Somebody has an idea how it could work in Qlik Sense?

Thanks in advance.

Greets

Benjamin