Nearly 25% of the world's population is Muslim

According to a recent comprehensive Pew Research study, the worldwide Muslim population comprises nearly 25% of the world's population. The Pew Research study notes, "A comprehensive demographic study of more than 200 countries finds that there are 1.57 billion Muslims of all ages living in the world today, representing 23% of an estimated 2009 world population of 6.8 billion."