I'm gonna go out on a limb and say that "Yahweh" is probably used more by Catholics than any other group.

I grew up Catholic too. People mostly said "God" but "Yahweh" was used a lot too, and I think I even heard "Jehova" a few times. (It was a pretty radical church.) But I've noticed that my friends who didn't grow up Catholic often don't even know the word "Yahweh."