Sustainable Development Goal 10 (SDG 10) aims to reduce income and wealth inequality within and among countries.The Gini Index provides a summary measure of the degree of income inequality within the Commonwealth countries. According to the World Bank, the Gini index measures the area between the Lorenz curve and a hypothetical line of absolute equality, expressed as a percentage of the maximum area under the line. A Lorenz curve plots the cumulative percentages of total income received against the cumulative number of recipients, starting with the poorest individual. Thus a Gini index of 0 represents perfect equality, while an index of 100 implies perfect inequality.Between 2000 and 2010, the average Commonwealth Gini Index was 41.1. 55.6% of countries (where data was available during this period) demonstrated higher levels of income inequality than the Commonwealth average, with the highest average levels of income inequality in the African region over the 11-year period.Note: No data was available for this period for Antigua and Barbuda, The Bahamas, Barbados, Belize, Brunei Darussalam, Dominica, Grenada, Guyana, India, Nauru, New Zealand, Seychelles, Singapore, St Kitts and Nevis, St Lucia, St Vincent and the Grenadines, and Trinidad and Tobago.