The Institute for Supply Management’s purchasing managers index for US non-manufacturing activity grew in August at the weakest pace in six years, MarketWatch reports. The Institute for Supply Management said its non-manufacturing index fell to 51.4% last month from 55.5% in July. While a reading above 50% signals that more businesses are expanding instead of contracting, it was the weakest showing since February 2010, shortly after the end of the Great Recession.