There used to be five levels, but only a 3-4% of Americans scored 376 or higher, out of 500. https://nces.ed.gov/pubs93/93275.pdf https://nces.ed.gov/pubs93/9

There used to be five levels, but only a 3-4% of Americans scored 376 or higher, out of 500. https://nces.ed.gov/pubs93/93275.pdf https://nces.ed.gov/pubs93/93275.pdf