"This index measures the degree of inequality in the distribution of family income in a country. The index is calculated from the Lorenz curve, in which cumulative family income is plotted against the number of families arranged from the poorest to the richest."
Data Source:
https://www.cia.gov/library/publications/the-world-factbook/rankorder/2172rank.html
Attribution:
http://www.flickr.com/photos/frugalbinx/6259662104/in/set-72157627802879403
