System Storage?

I just got an iphone6 and I set up a brand new apple id and have absolutely nothing on the phone except what came with it. I don't even have a single contact loaded. I have deleted just about every app that came with the phone and that was allowed to be deleted and it says my system storage is 15.16GB. Prior to deleting all the apps the storage was at 15.14GB. I only have 16gb total on the phone so just wondering how to get the system storage reduced when I have absolutely nothing on the phone. I even deleted the email app and didn't even have email set up on the phone. Help!