What do you mean by "proficiently literate"? The only definition I've ever seen of literacy is the ability to read/write, with no requirement that the writing

What do you mean by "proficiently literate"? The only definition I've ever seen of literacy is the ability to read/write, with no requirement that the writing be particularly eloquent. I don't know of any college that would accept illiterate students (with the possible exception of the truly blind, who might have accommodations to use audio for all tests). It would therefore be impossible for a graduate of a 4 year college to be illiterate.