This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionPrevailing religious population by country percentage.svg
English: This map shows the religion or lack-thereof practiced by the majority of persons in each country according to the Pew Research Center's 2010 study The Future of World Religions: Population Growth Projections, 2010-2050. These figures may incorporate populations of secular/nominal adherents as well as syncretist worshipers, although the concept of syncretism is disputed by some.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.