By John S. McClenahen Economists expected the service sector of the U.S. economy to grow more slowly in August. It didn't. At 65.1% on the Institute for Supply Management's (ISM) non-manufacturing business activity index, August was a repeat of July. Indeed, at 65.1% for the second consecutive month, it was the highest mark since ISM created the index in 1997. New orders, employment, order backlogs, imports, prices, and exports of services all increased in August, says ISM. Inventories decreased for the third consecutive month.