I can't remember where the statement was made in the nihongo-study-o-sphere, but some seem to be under the impression (I think I've heard it more than once) that one can't say "more than x" in Japanese, where x is a number. 以上 is "equal to or more than", and it's common, so I think this is where the idea that one can't do it comes from.
But I suggest 上回る. The opposite exists too, BTW: 下回る.
There is always a way to say something if you look for it.