I don't have numbers for you but can tell you that the majority of kids with ASD dxs are on the "milder" or "HFA" or "Aspergers" or even "PDD-NOS" end of the spectrum.

I can also tell you that I don't believe the 1/150 number (nor did I believe the 1/166 one.) Not that I have a better figure to offer. Just instinct.

And the LOOKS I get from the medical community when I say I want to work with kids with autism and I have no interest in a cure. . .