Economies are divided according to 2010 GNI per capita, calculated using the World Bank Atlas method.

Based on annual income, the four income groups are:

Low income, $1,005 or less
Lower middle income, $1,006 - $3,975
Upper middle income, $3,976 - $12,275
High income, $12,276 or more
Lower Middle Income include Angola, Cameroon, Djibouti, Lesotho, Namibia, Sudan, Swaziland.