No further dong rate changes this year, central bank says   Vietnam's central bank said it will not make any further changes to the dollar/dong exchange rate in 2015 after three devaluations this year. Deputy governor Nguyen Thi Hong of the State Bank of Vietnam (SBV) made the reassurance after the dong fell strongly against the dollar on the unofficial markets in Ho Chi Minh City on Monday. On the interbank markets the dong fell to its bottom of 22,547 per dollar on Monday, having lost around 5 percent so far this year, against an initial SBV pledge to let it slip no more than 2 percent for the whole of 2015. The SBV has changed the official exchange rate three times this year and also widened the dollar/dong trading band twice within this month, allowing the dong to move 3 percent each day around the official rate in interbank transactions. Reuters/TNN