there's a lot more than .02% that aren't actually muslim and will say they're persian and don't identify with a major religion as much as with their Persian heritage… and it is a clerical state so many are indeed forced to represent themselves as muslim, participate in islamic law and culture etc.. the idea that iran is 99% Islam is Iranian government propaganda. If you talk to Iranians abroad they'll say "no way, tons of iranians in Iran are not muslim"