Official currency reserves of developing world countries almost quadrupled over the last decade to $2.9 trillion. Reserves of industrialized countries went up by 150%. In 2005 reserves went up by 18% for developing countries and declined 1.5% for developed countries. 70% of total currency reserves are in developing countries. This is a huge accumulation of reserves by developing countries in a short period. In 2005 74% of overall reserves were in U.S. dollars. The reserves help countries pay bills and make investments. For developing countries having sufficient reserves helps in two other ways. The reserves are a buffer in emergencies , and means countries like Brazil and S. Korea don't have to turn to the IMF or the U.S. for assistance. Another way this helps is for countries like China to be able to use their reserves to keep their currencies from appreciating and maintain a competitive edge in exports.