Decrease iphone 4s battery life

My 4s is maybe around a year old. I have recently noticed that my battery seems to be draining faster than normal. After a full nights charge,and minimal use in the morning, maybe check the weather, send a txt or 2 etc... and when I get to work, I notice the charge is down to almost 90%. This is not at all how it used to perform in the past. I have tried some of the suggested changes in settings to help with battery life, but it doesnt seem to make a big difference? I can make it through a typical day with a charge, but if I am on the phone a little more than normal will have to charge it at some point. I was so impressed with the iphone battery life switching from a droid. Just wondering if this is normal for the age of my iphone?