The population of the Congo (2001 estimate) is 2,894,336, giving the nation an overall population density of 8 persons per sq km (22 per sq mi). About half the population follows orthodox religious beliefs. Most of the remainder are Christian, primarily members of the Roman Catholic church, which had nearly 1 million adherents in the Congo in the early 1990s. Muslims are 2 % of the population. Although French is the official language of the Congo, most people speak an African language.