Geography and demography are important factors in determining the nature of mental health care in Zambia, and more so than in some other developing countries, with which, however, it also shares important characteristics. Zambia, known as Northern Rhodesia until its independence in 1964, is situated in south central Africa and is completely landlocked, being surrounded by Zaire, Tanzania, Malawi, Mozambique, Zimbabwe, Botswana, Namibia, and Angola. Situated within the tropics, with a highly seasonal rainfall, it has recently experienced severe drought in its southern half. Although relatively large in area (752,614 square kilometers), its total population, based upon the 1990 census, is just over 7,818,500, but many parts are sparsely populated (density varying between 4 and 40 per square kilometer, with an average of 10.4--as compared with an average density of about 74 per square kilometer in Malawi and about 26 in Zimbabwe). Forty-two percent of the population is now resident in urban areas, a much higher proportion than in most African countries (in Tanzania, for example, the proportion is about 19 percent, and in Zimbabwe 25 percent). The low density of population and the inadequate road network contribute to the high cost of provision of services. As in most developing countries, there is a large child population, and 48.8 percent are below the age of fifteen years. The life expectancy at birth is 55.4 for males and 57.5 for females. The current population growth rate is 3.2 percent per annum overall, but the cities have shown spectacular growth. Thus Lusaka, the capital city, had an African population of only about 50,000 in 1954; ten years later it had about 150,000, when Zambia gained independence; the population was 400,000 at the time of a sample census in 1974; and it is currently estimated to be over 1.2 million.