Large declines in trucking and pipeline, coupled with smaller declines in rail carloads and rail intermodal, resulted in a decline in the total amount of U.S. for-hire freight movements in April from March.

The Transportation Department reported on Wednesday its Freight Transportation Services index fell 1.8% to 120.4 in April while the March index was revised downward to 122.6 from 122.9 in last month’s release.

FIgures for October through January were also revised down.

The April decrease was the largest monthly drop since January 2014 and brought the index to its lowest level since June 2014.

Compared to April 2014, the latest reading is up 0.3%, due to increases in air freight and waterborne freight transportation, according to the department.

The level of freight shipments in April measured by the Freight TSI was 2.3% below the all-time high level of 123.2 in November 2014. TSI records go back to 2000.

Since the beginning of 2015, the index has had alternating months of increases and decreases that have left it 1.7% lower than it was at the end of 2014. After dipping to 94.6 in April 2009, the index rose 27.2% in the succeeding 72 months.

The Freight TSI measures the month-to-month changes in for-hire freight shipments in tons and ton-miles, which are combined into one index and include the output from trucking, rail, inland waterways, pipelines and air freight.