Russia's rouble has slumped to a three-year low as oil prices keep hurting this oil price-dependent country. The rouble went down 0.5% to 32.9 roubles against the US dollar in early trading on Thursday. The Russian currency has been declining for seven days and lost some 3.5 % this week as oil prices went down, reported the Russian ITAR-TASS news agency today. The Russian Central Bank, which occasionally intervenes on the market to support the currency, has so far refrained from propping up the rouble. The oil benchmark for July delivery lost 0.1% to $87.9 in early trading at the New York Mercantile Exchange. Russian markets posted moderate gains Thursday morning. The Russian economy is strongly dependent on oil exports, but oil prices have slumped recently as the US dollar has risen to two-year highs against the euro amid the ongoing European debt crisis. Oil is priced in dollars and a stronger dollar makes the commodity more expensive, thus reducing demand.