Reserve currency economy, the German Deutsche Mark gained the status of the second most important reserve currency after the US dollar. When the euro was introduced on 1 January 1999, replacing the Mark, French franc and ten other European currencies, it inherited the status of a major reserve currency from the Mark. Since then, its contribution to official reserves has risen continually as banks seek to diversify their reserves, and trade in the eurozone continues to expand. Former U.S. Federal Reserve Chairman Alan Greenspan said in September 2007 that the euro could replace the U.S. dollar as the world's primary reserve currency.
Currency currency for each note of a foreign government held, as Ecuador currently does. Each currency typically has a main currency unit (the dollar, for example, or the euro) and a fractional unit, often defined as of the main unit: 100 cents = 1 dollar, 100 centimes = 1 franc, 100 pence = 1 pound, although units of or occasionally also occur. Some currencies do not have any smaller units at all, such as the Icelandic króna. Mauritania and Madagascar are the only remaining countries that do not use the decimal system; instead, the Mauritanian ouguiya is in theory divided into