Afghanistan, the world’s biggest exporter of raw opium for heroin, now also rivals Iran for the highest rates of addiction to the contraband drugs, the United Nations said. Some 2.7 per cent of the ravaged country’s adult population regularly use opiates. The findings put Afghanistan on a par with Iran, which in the 2009 report topped the opiate addiction rankings with rates ranging from 1.5 per cent to 3.2 per cent of population. Russia followed closely with a rate of 1.64 per cent. The global average is 0.3 per cent of population.