An early reading on employment last month suggests a marked cooling. The ADP National Employment Report says 158,000 jobs were added, fewer than the 200,000 projected by economists. Meanwhile, the Institute for Supply Management says its service-sector index fell from 56 in February to 54.4 in March. The data point to a softer first quarter than many expected. "If we do see a pullback, it's probably not going to be all that surprising, given the headwinds we have in front of us," said Sam Bullard, a senior economist at Wells Fargo.