I really can't give a number. Here as far as government business goes you must have some religion whether you are Muslim, Christian, Jewish, etc. I'm Muslim by birth certificate, but that's as far as it goes. I'm much interested in Christian religion. In our family it is much the same. I've actually some atheist family that are considered Muslim by birth certificate. (Birth certificates here have to indicate your religion)

But generally younglings are less religious and Iran's population is very young.

Women here have to cover their body except their face, hands and feet. You can not walk with a mini skirt here. No Sir, unless you are asking for a major trouble. But you don't have to wear a veil either. A small scarf over your head with a blouse and a pair of pants or a long skirt would do.

It is all right, you can ask any questions that I'm able to answer, but I'm off to bed now.