Bear in mind, though, that a good number of adepts don't really know the nature of their powers. From the Chapter 1 excerpt:
Fair enough, at least on the Adept level. But 7 million mages in the world still feels like an awfully high number, given how they've been portrayed thus far. Admittedly this portrayal could be slightly skewed by the fact that Alex happens to be one of the rarest types of mages out there.
My homebrew - If you use it, please let me know how it goes!