Demographics of atheism

53% of Bulgarians claim to be religious. Nearly a third (29%) do not perceive themselves as religious people, and a tenth are atheists (9%).

The number of Americans who don't affiliate with a particular religion has grown to 56 million in recent years, making the faith group researchers call "nones" the second-largest in total numbers behind evangelicals, according to a Pew Research Center study released May 12.

Christianity is still the dominant faith by far in the U.S.; 7 in 10 Americans identify with the tradition.