> I don't know if it's true > that does not seem unreasonable. My point is that what seems reasonable to someone that doesn't know anything about the subject

> I don't know if it's true > that does not seem unreasonable. My point is that what seems reasonable to someone that doesn't know anything about the subject means nothing, and could even end up being somewhat offensive. Try to reverse the logic and realize how absurd it would look to you: say a guy in middle east wanted to roughly estimate the number of Latin speakers and made the assumption that it should roughly be the same as Catholics. Wikipedia says there's ~2 billion muslims, and 400 millions Arabic-dialect speakers (native and non native). So on average 20% of muslims are able to understand basic arabic, I expect that not even half of those would be able to read and understand classical Arabic such as written in Quran.