Is this battery life normal for the iPhone 4S?

I'm really worried that my iPhone battery is bad. I just bought this phone used, and it seems to die quick.

Here's a link the the usage stats: Is this battery life normal for the iPhone 4S

Normal but could be better. If you don't use it, turn of location GPS and turn off bluetooth - they eat loads of battery.

Compared to other phones, it's not really that good, but compared to other iPhones, it's a decent battery life.