I think it depends and varys. Thor really stopped growing at about 1 yr. I thought he was done at about 6 months but then he "filled out". Kinda hard to explain if you don't know what I'm talking about but it was kinda like he wnet from puppy to Man dog!!!
Gained about 2 pounds but I couldn't tell, he didnt appear to get bigger at that stage, he just filled out.