The Word of Seven Billion
- The map shows population density; the brightest points are the highest densities. Each country is colored according to its average annual gross national income per capita, using categories established by the World Bank (see key below). Some nationsâ€” like economic powerhouses China and Indiaâ€”have an especially wide range of incomes. But as the two most populous countries, both are lower middle class when income is averaged per capita.