At high rpm, the capicitor don't discharged to the bottum.
Only at low rpm your using the max current.
The spark is also better at low rpm as high rpm

@Tung,

Was't better when I set the POP to 35 or 30 or 25 ?
I have to choose a number for the POP and I choose 40.
But you can change anything as you like into the Exelsheet.
Set yours to 36 and draw the curve between 27 and 15.