Nigeria Listeni/naɪˈdʒɪəriə/, officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country 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 in the Atlantic Ocean. The site of many ancient kingdoms and empires, the modern political state of Nigeria has its origins in the British colonization of the region during the late nineteenth to early twentieth centuries; it emerged from the combination of two neighboring British protectorates: the Southern Nigeria Protectorate and Northern Nigeria Protectorate. During the colonial period, the British set up administrative and legal structures whilst retaining traditional chiefdoms. Nigeria achieved independence in 1960, but plunged into civil war several years later. It has since alternated between democratically-elected civilian governments and military dictatorships, with its 2011 presidential elections being viewed as the first to be conducted reasonably freely and fairly. Nigeria is often referred to as the "Giant of Africa", due to its large population and economy. With approximately 174 million inhabitants, Nigeria is the most populous country in Africa and the seventh most populous country in the world. The country is inhabited by over 500 ethnic groups, of which the three largest are the Hausa, Igbo and Yoruba. Regarding religion, Nigeria is roughly divided in half between Christians, who live mostly in the southern and central parts of the country, and Muslims, concentrated mostly in the northern and southwestern regions. A minority of the population practice religions indigenous to Nigeria, such as those native to Igbo and Yoruba peoples. In 2014, Nigeria's economy (GDP) became the largest in Africa, worth more than $500 billion, and overtook South Africa to become the world's 26th largest economy. Furthermore, the debt-to-GDP ratio is only 11 percent (8 percent below the 2012 ratio). By 2050, Nigeria is expected to become one of the world's top 20 economies. The country's oil reserves have played a major role in its growing wealth and influence. Nigeria is considered to be an Emerging market by the World Bank and has been identified as a regional power in Africa. It is also a member of the MINT group of countries, which are widely seen as the globe's next "BRIC-like" economies. It is also listed among the "Next Eleven" economies set to become among the biggest in the world. Nigeria is a member of the Commonwealth of Nations, the African Union, OPEC, and the United Nations among other international organizations.