No data exists for that because the definition of illiteracy depends too strongly on the axe being ground. Everything from 1% to 66% illiteracy has been attemp

No data exists for that because the definition of illiteracy depends too strongly on the axe being ground. Everything from 1% to 66% illiteracy has been attempted to sell to people. It does seem that illiteracy clusters with various citizenship status, racial and other demographics, simple age distribution of a geographic location, and socioeconomic level to an extent that if you successfully filter those effects out you end up with a boring flat line at 100% literacy when ends up meaning nothing. The largest factor is literacy graphs and maps are basically a restatement of immigration data.