We got a lot of ruin, law text and monument about daily life, xomplaint etc from the Roman Empire. But reading and writing it's hard and not everybody can afford the education to mastering this skills. So, did we know what % of the population was capable of this ? Public monument, tomb and other stuff was readablz by a vast portion of population or one-ortwo people in a city read everyrhing for everyone ?
This is a common question on the sub. See this answer from a while back, and also this thread on Roman education as it pertains to literacy.