The Institute for Supply Management (ISM) reported on Thursday its non-manufacturing index (NMI) came in at 52.6 in August, which was 3.8 percentage points lower than the August reading of 56.4 percent. The September reading pointed to the slowest expansion in the services sector since August 2016.

Economists forecast the index to decrease to 55.1 last month. A reading above 50 signals expansion, while a reading below 50 indicates contraction.

The 13 non-manufacturing industries reported growth last month, the ISM said, adding that respondents were mostly concerned about tariffs, labor resources and the direction of the economy.

According to the report, the ISM’s non-manufacturing business activity measure fell to 55.2 percent, 6.3 percentage points lower than the August reading of 61.5 percent. That reflected growth for the 122nd consecutive month, at a slower rate in August. The new orders gauge dropped to 53.7 percent, down 6.6 percentage points from the reading of 60.3 percent in August. The Employment indicator decreased 2.7 percentage points in September to 50.4 percent from the August reading of 53.1 percent. Meanwhile, the Prices Index rose 1.8 percentage points from the August reading of 58.2 percent to 60 percent, indicating that prices increased in September for the 28th consecutive month.