The attention of many Africanists is now absorbed by the extraordinary rate of social-demographic development in the countries of tropical Africa during recent decades, the rapid change of the demographic balance between town and country, and the intensive growth of towns. Africa is now ahead of all other continents in the rate of urban population growth, as indicated by Table I; this shows ten-year rates of growth in the total population of towns with over 20,000 inhabitants, for eight major regions and for the world as a whole. Africa is the only region whose rate of urban growth has accelerated from decade to decade since 1920; during 1950–60, she overtook Latin America, and her growth rate of 69 per cent was well above the world average.