Just got this from Worldpopulation.com about the U.S., but haven't looked into the other countries yet:

"According to the National Center for Education Statistics, about four out of five U.S. adults (79%) have medium to high English literacy skills. These literacy levels are sufficient to compare and contrast information, paraphrase, and make low-level inferences. This means that about one in five U.S. adults (21%) have low literacy skills, translating to about 43.0 million adults.

Of those who have low English literacy skills, 35% are White, 2% of whom are born outside of the U.S.; 23% are Black, 3% of whom are born outside of the U.S.; 34% are Hispanic, 24% of whom are born outside of the U.S.; 8% are of other races/ethnicities. Non-U.S.-born adults comprise 34% of the U.S. population with low literacy skills."