That would leave 90% of all copies in existence raw.
I have to very respectfully disagree.
Over 50%, if not well over 50% of the copies we see made available are slabbed.
Very unlikely that 90% of all remaining copies are raw.
Don't know if you saw it, but over in the AF #15 thread, G.A.tor asserted that he wouldn't be surprised if there were 12,500 to 25,000 copies of AF #15 (5-10% of a reported 250,000 original print run). He's not the final authority on this discussion, but I think his opinion has value simply because of his experience in the hobby. IF he's in the ball park, then something relatively similar, it seems, would be going on with ASM #1.
CGC will be celebrating their 13th anniversary come January and even though that's a decent chunk of time, it's not quite even a generation. So I think after, say, 25 years it'll be interesting to see the figures (but I do think there's tons of collectors, as scooter99 suggests, that do not have their copies slabbed).
Incidentally, in January of this year I noted how many total copies of Action Comics #1, Detective Comics #27, and Amazing Fantasy #15 there were on the CGC census. In ten months, here's how things have changed: over 200 more copies of AF #15; 4 more of Tec #27; and 2 more of Action #1.