In article , RicodJour wrote:

And then seriously another study by Science Daily says
"A recent study conducted by the Center for Injury Research and Policy
of The Research Institute at Nationwide Children's Hospital found that
from 1990-2007, an estimated 565,670 non-occupational table saw-
related injuries were treated in US hospital emergency departments,
averaging 31,500 injuries per year."

Again note: "Non-occupational" I think pros are more careful.

My question is if 31,500 went to the ER, what did the other 534,170
(estimated) people do (assuming one injury each!) and how did the
study know how to estimate it with that degree of accuracy?

I think you missed the point: 565,670 injuries in an 18-year period is
(approximately) 31,500 *per year*.