Disability Population In U.S. and The World

I have been meaning looking up the break down of the disabled population since Autism is about the only one you really hear people taking about.

Here is one link, but not really want I was looking for: Facts About Disability in the U.S. Population.

When I was reading this one, I got a bit offended. I do realize that they are generalizing, but not everyone that is disabled comes from low educated and from low income areas: World Facts and Statistics on Disabilities and Disability Issues.

When it comes down to it, I think people do not know what they are taking about when keeping tract of the  disabled population. I found it too general and a lot of the language is offensive.  For example,  Jonathan's 40% Rule: Hearing Impairment is like alcohol and drug abuse--there's tremendous denial. Source Maybe for people who are growing older, but I do not think that statement would go over well at Gallaudet U. or in the deaf community.

I think its hysterical that the CDC keeps stats on "Cerebral Palsy Occurrence in the US", maybe this why people still think of CP  as a decease and an illness. Also notes that Autism and Developmental Disabilities are included in these statistics. Is the CDC just counting people with combined disabilities, or just grouping everything together? If the CDC keeps tract of "Cerebral Palsy Occurrence", does this mean we could of a CP apocalypse and take over the world?

So this  makes me wonder how each organization comes up with statistics? I would also like  to ask how the organizations defining a disability and what is a person has multiple disabilities?