Reserve currency before the beginning of the worldwide credit crunch related recession and Eurozone crisis, which harmed the euro and slowed its adoption. Since 2009, the reserve currency use of the euro has continued to drop, down to 23.9 percent in 2013. The Dutch guilder was the "de facto" reserve currency in Europe in 17th and 18th centuries. The United Kingdom's pound sterling was the primary reserve currency of much of the world in the 19th century and first half of the 20th century. The emergence of the USA as an economic superpower, and the establishment of the U.S. Federal Reserve System
WCU – World Currency Unit of this unit would rise if other currencies represented in the basket appreciate against the US dollar. Savers purchasing such bonds would not only enjoy protection against inflation, but would benefit from the diversification of exchange risks. The WCU could be used for the pricing of commodities such as oil, precious metals, and agricultural products, which are typically quoted in US dollars. Of course, historical prices of commodities quoted in US dollars could also be converted into prices in WCUs to provide indications on trends in the real prices of these commodities. WCU – World Currency Unit The World Currency