Total turnover of commodity exchanges dropprd by nearly 14 per cent during the first fortnight of this month to Rs 5.13 lakh crore on account of thin trade in bullion and energy. "Total value of trading at the commodity exchanges during the fortnight, April 1, 2012 to April 15, 2012, was Rs 5,13,051.68 crore. The corresponding figures for the fortnight in the previous year was Rs 5,93,198.82 crore," the Forward Markets Commission said in a report.