Original: In the US, 14% of the adult population is at the "below basic" level for prose literacy; 12% are at the "below  basic" level for document literacy; and 22% are at that level for quantitative literacy.
Simplified: In the US, 14% of adults are  at the "below basic" level for prose literacy; 12% are at the "below  basic" level for document literacy; and 22% are at that level for quantitative literacy.