average age?!

I heard on the Today Show this morning that the average age of an American mother is 25 years old. I was shocked! That seems like it is so young to be the average now a days with so many women having healthy, happy babies when they are older. Hmm, makes ya wonder how they collect the stats? Maybe younger women end up having more babies? I want the stat on the average age of a first time mom, only counting first babies just for curiosities sake.