Among those whose fathers were between 15 and 29 when they were born, the rate of autism was six in every 10,000, rising to nine in every 10,000 when fathers were aged 30 to 39 (1.6 times higher).
In the group whose fathers were aged 40 to 49, the rate rose to 32 in 10,000 (5.75 times higher).
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Did you miss the stats for the 30-39 year old group. They are listed in the original article for all to see.
My bad.
I am headed there now, but I am not so much interested in the complete summary as I am in detailed description of the methodology, sample size, control groups, confounding factors, etc.