Many different ethnic groups lived in the area when the Portuguese arrived in the late 15th century and began a trade in ivory and slaves. In the late 19th century, Germany declared Cameroon a protectorate, which lasted until the end of World War I, when the land was divided between the French and the British. After World War II, there were moves in each part towards self-rule and independence, but by 1961, former French Cameroon and part of British Cameroon merged to become one country (the northern part of British Cameroon joined Nigeria). The economy is dependent upon timber resources and agriculture. Cameroon holds a significant reserve of natural gas, which is relatively unexploited, and petroleum products constitute more than half of all exports. The majority of the people are farmers inhabiting small villages in southern and central Cameroon. Many of the northern people were semi-nomadic herders. Despite movement towards democratic reform, the process of democratization remains slow. Christianity in Cameroon is closely linked with the colonial history of the country. In 2005, the Federation of Protestant Churches and Missions in Cameroon, which was originally organized in 1943, was restructured to become the Council of Protestant Churches of Cameroon. Yaoundé, the capital, has two important institutions for the Protestant churches in West Africa: a theological faculty, and a Centre for Christian Literature (CLE).