English: Graph of the official exchange rate of the Belarusian ruble (BYR) vs key foreign currencies, in 2006-01-01...2015-01-19. US dollar (USD, used e.g. in trade of oil & natural gas), euro (EUR) and Russian ruble (RUB) are the three most important foreign currencies used in the Belarusian economy. The exchange rate shown is that available from the National Bank of the Republic of Belarus (http://www.nbrb.by/engl/statistics/Rates/RatesDaily.asp). Note the two strong devaluations in 2011 and one in early 2015; seen as sharp drop of the BYR exchange rate, as seen in May 24, 2011, in October 21, 2011 and in early January 2015 values (actually stepwise devaluation occurring in December 30, 2014, in January 6, 9, and 15, 2015). Prior to January 2015 devaluation, the sharp weakening of Russian ruble since summer 2014 could be seen.