The country has an area of 364,900 square miles and a population of 40 million, of which 38.8 million live on the mainland and 1.2 million on the Zanzibar archipelago, which has a president and semiautonomous political structure separate from the mainland political system. The Government does not gather religious identification data in its census as a matter of policy. However, recent information suggests that 62 percent of the population is Christian, 35 percent is Muslim, and 3 percent are members of other religious groups.
On the mainland, Muslim communities are concentrated in coastal areas, with some large Muslim minorities also in inland urban areas. Between 80 and 90 percent of the Muslim population is Sunni; the remainder consists of several Shi'a subgroups, mostly of Asian descent. The Christian population is mostly composed of Roman Catholics, Protestants, Pentecostals, Seventh-day Adventists, members of The Church of Jesus Christ of Latter-day Saints (Mormons), and Jehovah's Witnesses. Other active religious groups include Buddhists, Hindus, Sikhs, and Baha'is. Zanzibar is 98 percent Muslim.