Moffat said Count Again.

Has anyone else counted? Has anyone else figured it out?
Just how many regenerations has the Doctor really had? 12...including John Hurt and Peter Capaldi. Wanna know how I got to this conclusion?

William-0 (He isn't a regeneration he's a birth form)
Pat-1
Jon-2
Tom-3
Peter D-4
Colin-5
Sly-6
Paul-7
John Hurt- 8
Chris-9
David-10
Matt-11
Peter C-12

And thats what Moffat meant by count again...Do you have other theories?