<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> Adherents of Islam constitute the world's second largest religious group . According to a study in 2015, Islam has 1.8 billion adherents, making up about 24% of the world population . Most Muslims are either of two denominations: Sunni (80 - 90%, roughly 1.5 billion people) or Shia (10--20%, roughly 170 - 340 million people). Islam is the dominant religion in the Central Asia, Indonesia, Middle East, South Asia, North Africa, the Sahel and some other parts of Asia . The diverse Asia - Pacific region contains the highest number of Muslims in the world, easily surpassing the Middle East and North Africa . </P> <P> About 31% of all Muslims are of South Asian origin, therefore South Asia contains the largest population of Muslims in the world . Within this region, however, Muslims are second in numbers to Hindus, as Muslims are a majority in Pakistan and Bangladesh, but not India . </P>

Where does islam rank in size on the list of the world’s religions