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 West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in the north. Its coast in the south lies on the Gulf of Guinea on the Atlantic Ocean.
Nigeria is a federal republic modeled after the United States, with executive power exercised by the president. The government of Nigeria is also influenced by the Westminster System model in the composition and management of the upper and lower houses of a bicameral legislature.