> So the actual number is probably much higher.

Why? Can you please walk me through your reasoning?

Autism is now well known and fairly easily identifiable.

Child care centers, schools, etc all have staff who can identify development issues and will refer to a trained medical professional to diagnose. At least in moderately sized cities.

That was not the case 40 years ago.

It is higher, because women have autism too - through less often and they are better able to masks it.

Nevertheless, majority of those diagnosed are not particularly talented at programming or it just happened that they became obsessed over something else.