Notes: OPEC (Organization of Petroleum Exporting Countries) members are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Angola joined OPEC in January 2007. Ecuador was a member of OPEC from 1973-1992, and rejoined OPEC in November 2007. Gabon was a member from 1975-1994. Indonesia withdrew from OPEC in May 2008.
Source: U.S. Department of Energy, Energy Information Administration, Monthly Energy Review (Washington, DC: August 2011), tables 3.3c and 3.3d, available at http://www.eia.doe.gov/emeu/mer/petro.html as of September 2011.