Source: United Nations, Department of Economic and Social Affairs, Population Division. World Urbanization Prospects: The 2011 Revision. New York: United Nations.
Metropolitan Areas with more than 10 million Inhabitants, 2010 (in millions)
A high proportion of the world's population lives in large urban agglomerations. There were 83 metropolitan areas with populations of more than 1 million in 1950, a figure that increased to 160 by 1975. In 2000, there are over 348 such cities and this number surged to 441 in 2010. If cities above 10 million are considered, 21 existed in 2010 with Tokyo, the largest, having 36.6 million inhabitants. In the span of half a century several cities have more than tripled their population, underlining that urbanization has been the world's leading socioeconomic change for at least half a century.