I got to see his stand up in Toronto just a few months ago, which by the way was absolutely amazing. If you rent the documentry Jerry made called Comedian, then you can get more insight on what comedians have to go through with their material.
Based on what I remember though, it is typical for comedians to repeat their material.
Although a year in between the times you seen him sounds like a long time to stick with EXACTLY the same material, it's understandable. Also from the documentry, we can see Orny Adams showing us all the material he performs depending on the type of audience. So I think that you seeing him at the same place both times also may influence what material he does.
Anyways, I suggest just renting Comedian, it's actually quite interesting.