World religion

The CIA’s World Fact Book (which can be found here: https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html) reports these statistics on the belief systems of the world’s population. Recently Christianity, though still the predominant religion, has been on the decline; in contrast, the number of people not adhering to any religion has been increasing.

Religious Affiliation: Percentage of the World Population
Christian: 33.32%
-Roman Catholic: 16.99%
-Protestant: 5.78%
-Christian Orthodox: 3.53%
-Anglican: 1.25%
Muslim: 21.01%
Hindu: 13.26%
Buddhist: 5.84%
Sikh: .35%
Jewish: .23%
Baha’i: .12%
Other religions: 11.78%
None: 11.77%
Atheist: 2.32%

"CIA - The World Factbook." Central Intelligence Agency. Web. 1 Dec. 2010. .