Next to China, India is the country with the largest number of inhabitants in the world. Facing the fact that almost one thousand million people are living in India it is amazing that they occupy only 2.4 % of the earth's surface. The average population density is 298 inhabitants per square km. In some areas, population density reaches over 1000 inhabitants per km square for which two reasons can be mentioned. First, population remains concentrated in the big cities and around the fertile riverbeds of the Ganges and second huge parts of the country remain uninhabitable because they are covered either by desert or by high mountains. The average life expectancy is 58 years, the share of young people under the age of 18 is over 40%.Around ¾ of Indians are living in the rural area, ¼ of the population lives in cities. The biggest cities are Kolkata (formerly Calcutta), Mumbai (formerly Bombay), Delhi and Chennai (formerly Madras). About 5 million Indians are living abroad, primarily in South and East Africa, in South-East-Asia, North America and around the Persian Gulf.