Religious affiliation in Nigeria is strongly related to ethnicity, with rather distinct regional divisions between ethnic groups. The northern states, dominated by the Hausa and Fulani groups, are predominantly Muslim while the southern ethnic groups have a large number of Christians. In the southwest, there is no predominant religion.
Nigeria has experienced a population explosion for at least the last 50 years due to very high fertility rates, quadrupling its population during this time. Growth was fastest in the 1980s, after child mortality had dropped sharply, and has slowed slightly since then as the birth rate has sunk slightly. According to the 2012 revison of the World Population Prospects the total population was 159,708,000 in 2010, compared to only 37,860,000 in 1950. The proportion of children below the age of 15 in 2010 was 44.0%, 53.2% was between 15 and 65 years of age, while 2.7% was 65 years or older.
Nigeria is located in western Africa on the Gulf of Guinea and has a total area of 923,768 km2 (356,669 sq mi),[93] making it the world's 32nd-largest country (after Tanzania). It is comparable in size to Venezuela, and is about twice the size of the U.S. state of California. It shares a 4,047-kilometre (2,515 mi) border with Benin (773 km), Niger (1497 km), Chad (87 km), Cameroon (1690 km), and has a coastline of at least 853 km.[94] Nigeria lies between latitudes 4° and 14°N, and longitudes 2° and 15°E.