The Russian central bank has dropped its key interest rate from 17% to 15% as the outlook for the country's economy in weakens. The Bank of Russia hikes interest rates by 6.5% last month in a shock decision that came at 1am local time. The measure was intended to head off a collapse in the value of the ruble, which fell to an all-time-low of 80 rubles to the dollar and 100 rubles to the euro in December.