http://abcnews.go.com/Politics/story?id=7513343&page=1

Historically, the percentage of Americans who said they had no religious
affiliation (pollsters refer to this group as the "nones") has been very
small -- hovering between 5 percent and 10 percent. However, Putnam says
the percentage of "nones" has now skyrocketed to between 30 percent and
40 percent among younger Americans.