Battery dropping even on doze nexus 6p

I left my nexus 6p for 8 hours on the desk and when I woke up the battery dropped from 60 to 53 percent. This wasn't normal to doze. Usually I'd get 3 or 4 percent.. I checked the battery usage settings and everything was fine the phone was dozing and wifi was off the whole time. Perhaps the culprit was the mobile data usage showing light green color for the whole 8 hours. I'll post a pic of it below. Thanks for the help.