US Dollar is the basic unit of currency of Ecuador, Guam, Hawaii, Caroline Islands, Northern Mariana Islands, Marshall Islands, U.S. Virgin Islands, British Virgin Islands, Marshall Islands, Palau, Puerto Rico, Timor, Turk and Caicos Islands, Zimbabwe. The currency ISO code of US Dollar is USD. USD has a floating rate. Also used as an official currency by Puerto Rico. US Dollar had a depreciation of 10,4 % against euro in 2006.
The end of the international monetary system of Bretton Woods in 1973 caused a division of the international economy in monetary areas. The USD area concerns mainly the American continent. On August 15, 1971, the American monetary authorities decided to let the USD float. The suspension of the US dollar convertibility has been made official on 1976, according to the Jamaica agreements. The agreements of Bretton Woods introduced after World War II a system of fixed exchange rates (Gold exchange standard) in which each member of the IMF set a parity for its currency against gold or the dollar and undertook to keep fluctuations to +/-1% through intervention in the market by its Central Bank. The U.S. is required to peg the dollar to gold and other countries to peg their currencies to the dollar.