American Cattle Numbers

I was just curious if there was any resources that showed annual purebred cattle registrations in the US, specifically for Shorthorns. I know in Canada they are available through the Canadian Livestock Records Corporation, but I can't seem to find any American stats. Thanks in advance.

My professor gave us these numbers a few days ago for the top 5 breeds (Purebred  Registrations).
                          2008            2011
1) Angus          333,766      282,911
2)Charolais      65,954        56,291 females and 31,910 new
3)Hereford        63,943        65,000
4)Red Angus    48,061        60,548
5)Simmental    45,500        52,251

I'm still not sure what happened or how he figured the Charolais numbers. Sorry I can't help you with the Shorts.