You can't spell autism without u.

Autism’s prevalence has skyrocketed.

Ten years ago, autism’s estimated prevalence was 1 in 166. Today it’s 1 in 68 – an increase of more than 100% in one decade.

However, autism’s prevalence may be even higher.

In a landmark study funded by Autism Speaks, screeners went into schools in South Korea and found 1 in 38 children affected by autism, most of them previously undiagnosed. Since then, Autism Speaks has worked with the CDC to conduct a similar direct-screening study in the United States. The results are expected to be published this spring (2016).

Source:
https://www.autismspeaks.org/news/news-item/10-years-progress-what-we039ve-learned-about-autism