nexus 5 - Battery percentages per app nowhere near total

when I look at my Nexus 5 with android 5.1. battery screen, I can see something like this:

^{Screenshots (click images for larger variants)}

Sum of all per-app percentages in list is 10. However as you can see, there is 60% battery consumed (40% remaining). So, what is the deal here? Who consumed 50% battery? Or what do the percentages next to apps mean?

As you can see, screen was on just for few short times, the same for awake, and yet battery life about 18 hours? I dont get it.

Also, I found this issue reported on AOSP, but noone from google seems to care: https://code.google.com/p/android/issues/detail?id=80131