The Institute for Supply Management’s manufacturing purchasing managers index rose to its highest reading since June 2011 as economic activity in the U.S. manufacturing sector expanded at a faster pace in April.

The institute’s manufacturing index rose to a reading of 54.8 in April from 53.4 in March. Readings above 50 indicate expansion. The average reading for the past 12 months was 53.2 with the high reading in June at 55.8.

The employment portion of the index rose as well, going to a reading of 57.3 in April from 56.1 in March.