The following statistics reveal some good news and bad news for atheists. First, here are the good news stats for atheists:

• A 2012 poll suggests that 1 in 20 (or 5 percent) of Americans identify themselves as atheists. (The participants were asked to identify themselves as either "a religious person, a nonreligious person, or a convinced atheist.") That's a fivefold increase from the last time the survey was taken in 2005.
• The 2012 poll also surveyed 50,000 people from 57 countries on 5 continents and found that 13 percent of people worldwide identify themselves as an atheist. (Note that this survey also included respondents from China where 47 percent of the population consists of self-identified atheists.)

But here's the bad news stat for atheists:

• According to data analyzed from a 2008 Pew Forum survey, atheists ranked last in the category of "religious retention rates." Specifically, only 30 percent of respondents who were raised in an atheistic home are still atheists as an adult.
• In other words, these statistics reveal that U.S. atheists are for the most part "made" as adults after being raised in another faith. As one summary of the Pew Forum survey wrote, "It appears to be much more challenging to raise one's child as an atheist and have them maintain this identity in their life."