If you're so good with numbers then you should know that your "65%" of battery use from the screen is when the phone is on, the screen is on and it's all on idle mode.

The screen can be off and the phone can have 5 apps running in the background. the 65% no longer applies.

The screen can be on and the phone can be running 5 apps, streaming data, converting video, converting audio, refreshing the app. The 65% no longer applies.

Your analysis is objective and primative.

Percentage of battery use is subjective, it's not a valid mesure of battery capacity.