I don't have the exact number. Part of that is because, respectfully, the Down Syndrome Resource Foundation works more directly with, obviously, Down syndrome. But it would be a significant part of the population when you consider the simple fact that it includes those who are on the autism spectrum, which now we've recognized, after years of research—and the medical data backs this up—that people we thought had no development disability, do in fact do. I don't have an exact number, but I don't think I would be exaggerating by saying it is significant.
On April 23rd, 2021. See this statement in context.