I've found solution - more complex but working.
I disabled accumulation option for all expressions and use Above() function to accumulate values in the same way.
I think that accumulation option caused the problem, because calculation of expression was performed for every value of dimension (Q1, Q2..) and the results were summed.
Expressions are not so simple as it could be using accumulation mode in chart, so if somebody know simpler solution (simpler expressions or other solution) to obtain such an effect as above, please let me know.
File with my solution in attachment.
solutiont.qvw 129.5 K