I looked at that website...there is nothing concrete there.
One of the BIGGEST things is that autism is BETTER DIAGNOSED at a much earlier age compared to the 1970s.
When children were developmentally delayed at the turn of the century and into the 1960s, most children were labelled as mentally handicapped and placed into institutions. No one really knew what to do with these children and few valued them as human beings. Thus, research and really finding out the differences between things like down's syndrome and autism weren't important to us as a society...American, Canadian, European or otherwise.
Further more, the second world war brought the extermination of people with disabilites in a lot of European countries that were invaded by Nazi Germany. Thus...the face of people with disabilities in European history CHANGED. Not only that, but when a CONTINENT is trying to rebuild its food sources, structures, economy and health systems for its general public, the funding and the focus just couldn't be placed on things like intellectual disabilities.
So...you have to look at the research and the histories that are kept in order to make a good judgement on this.
AHHHH!!! Gosh, Doc...we haven't had a vaccine topic like this here in a while! It's REALLY great to have threads like this!