Don't try to play the SOT game. It's a waste of your time. These high so numbers (higher than 4-5 hrs) is not under normal use. As long as your device doesn't die before the end of the day, then your battery is fine.
Someone who listens to music all day with the screen off will have zero hours sot, but someone who just keeps their screen awake while reading an e-book on WiFi will easily get 8 hours sot.