Your battery looks about as good as mine did before the jailbreak. 9-10 hours usage is what other people on this thread would kill to have. Talk about our first world problems. You're disappointed in that and I'm disappointed when my jailbreak gives me anything close to 12 hours because that's my new minimum haha (a week ago that would have been amazing now it's just average for me).
Anything with bad reception will drain the battery. The fastest I've seen my battery drain was in Costco (entire warehouse is made of concrete walls) and at my mechanic where my signal constantly switched between LTE and 3G every few minutes.
Mail is probably also draining it. Exchange is a known battery drainer due to how the protocol works. It has to use a keep-alive connection open the entire day for it's push email. There was a Verge article explaining it a few years ago back when I had an iPhone 4s. I remember reading it and switching to the gmail app instead and my battery life went from like 4 hours to 6 just with that change.
