After rising for two weeks in a row, the average price of diesel fuel dropped again, according to the latest numbers from the Energy Department.

The price of a gallon of on-highway diesel fuel decreased by 2.5 cents nationally to $2.531 per gallon. With the dramatic decreases in the price of oil this year, diesel prices are still far below 2014-levels and is nearly $1.13 cheaper than this same week a year ago.

Prices were down in most regions with the largest decrease occurring in the Midwest with a 4.2-cent drop. The price increased slightly in the Rocky Mountain region by 0.7 cents.

The price of a gallon of gasoline decreased by 6 cents, dropping to an average of $2.277 per gallon. The price is 84.3 cents cheaper than the same time a year ago.

The largest price drop was in the Midwest with a 10.5-cent per gallon drop and the smallest price drop was in the Central Atlantic region, dropping by 1.1 cents.

Crude oil prices were down on Monday, dragged down by news of higher production coming from Iran and subdued growth in China’s economy, according to a report in the Wall Street Journal.

While the growth numbers out of China were not a surprise to investors, it still had a negative effect on energy prices as China makes up a substantial part of the global demand for crude oil. With supply already outstripping demand with high U.S. shale oil production, the announcement that Iran would increase its oil production also caused prices to fall.