You'd have to exclude everybody under 7 or so, everybody who is illiterate (in this very expansive sense), and those that are Muslim but do not read Arabic and

You'd have to exclude everybody under 7 or so, everybody who is illiterate (in this very expansive sense), and those that are Muslim but do not read Arabic and do everything in translation. That might be a small group though and probably outweighed by all the non-Muslim Arabic readers (for instance I work with 2 Egyptians, one is Coptic and one is ex-Muslim and both can easily read Arabic).