Nigeria is the number one source country for West African immigrants coming to the United States and is second to Ghana for immigration to Canada. In the U.S. census of 2000 and the Canadian census of 2001, 165,481 Americans and 9,530 Canadians claimed Nigerian descent. Nigerians live throughout the United States, but the greatest concentrations are found in Texas, California, and New York. Most Canadian Nigerians live in Ontario. Nigeria occupies 351,200 square miles on the southern coast of West Africa. It is bordered by Benin on the west, Niger on the north, and Chad and Cameroon on the east. The population of Nigeria, estimated at 126,635,626 in 2002, is divided both ethnically and religiously. There are 10 major ethnic groups and almost 250 smaller ones, the largest being the Yoruba (17.5 percent), the Hausa (17.2 percent), the Ibo (or Igbo, 13.3 percent), and the Fulani (10.7 percent). Christians and Muslims each make up about 45 percent of the population, with the former concentrated in the south and the latter in the north. Although the Portuguese first visited Nigeria in the 15th century, the region remained under the control of hundreds of tribes until the 1860s, when Great Britain began to extend its influence inland from coastal trading ports. By 1903, British control was virtually complete, and by 1914, the approximate borders of the modern country had been established. Nigeria gained its independence in 1960. After a brief period of civilian rule, a series of coups, assassinations, and the secession of the state of Biafra in 1966 led to one of the bloodiest civil wars on the continent. By the time Biafra was subdued in 1970, some 2 million Nigerians had died. The country remained one of the most corrupt and politically unstable throughout the 20th century. Apart from the descendants of slaves who had been brought to the Americas in the 17th and 18th centuries (see African forced migration), there were almost no Nigerians in the United States prior to the 1970s. Between World War I (1914–18) and World War II (1939–45), a number of Nigerian nationalists traveled to and were sometimes educated in the United States. These included Nnamdi Azikiwe, first president of Nigeria, who studied at Lincoln University in Pennsylvania and Howard University in Washington, D.C. The numbers of Nigerians remained small, however, never totaling more than 30. The oil boom of the 1970s enabled Nigeria to send an increasing number of students abroad for education. During the late 1970s and 1980s, Nigeria was among the top six countries sending students to the United States. With the sharp decline of the Nigerian economy in the 1980s, an increasing number of Nigerians stayed in the United States and eventually brought their families to join them. As a result, between 1990 and 2000, the Nigerian-American population grew from 91,688 to 165,481. Between 1992 and 2002, immigration from Nigeria averaged almost 7,000 per year. Many Nigerians are well educated and have thus spread widely throughout the country following professional and academic careers. It is difficult to ascertain the number of Nigerians who immigrated to Canada prior to 1973 because they were previously included in a general African category. There was, however, already a small stream of refugees from the civil war of the 1960s. Of 8,850 Nigerian immigrants in Canada in 2001, 240 came before 1971. Between 1971 and 1990, another 2,385 arrived. The rate of immigration increased significantly in the 1990s. Between 1991 and 2001, 70 percent of the Nigerian immigrant population arrived in Canada. During the 1980s, Nigeria was sometimes in the top 10 source countries sending students to Canadian universities. Many have stayed to work in the civil service, medicine, law, engineering, or other professional areas.