According to a 2014 estimate by the ''CIA World Factbook'', 61.4% of the population was Christian, 35.2% was Muslim, 1.8% practised traditional African religions, 1.4% were unaffiliated with any religion, and 0.2% followed other religions. Nearly the entire population of Zanzibar is Muslim. Of Muslims, 16% are Ahmadiyya, 20% are non-denominational Muslims, 40% are Sunni, 20 per cent are Shia, and 4% are Sufi.