The Institute for Supply Management’s purchasing managers index for US manufacturing decelerated to a reading of 51.1 in August, down from July’s reading of 52.7. The reading indicates continued expansion, but at a slower pace.

Readings above 50 indicate growth.

Reuters reports the reading fell further than expectations that the pace would edge down to 52.6, according to a Reuters poll of economists, and marks the lowest reading since May 2013.

The employment portion of the index also fell to a reading of 51.2 in August from 52.7 in July in June, reflecting growing employment levels from July but at a slower rate. The reading marked its lowest level since April, according to Reuters.