[EdinSumar]

It does happen, especially "human" deities tend to draw a lot of non-human worshippers and even Clerics. It happens more rarely amongst non-human religions. Of course, it also depends upon the mindset of the adherents and how welcoming they are to people of that specific race.

I would say that in general, between 1-5% of all Clerics of Faerunian "Human" deities are non-human, while amongst racial Faerunian deities it is generally 0,1-0,5%. There are exceptions, of course, Sune has a lot of Elven Clerics, for example, while you will -never- see a Moon Elf adherent of Llolth.