The average price of diesel fuel fell again last week, continuing a steady decline in prices that began over a month ago, according to the latest numbers from the Energy Department.

The price of on-highway diesel fuel dropped by 2.3 cents last week, falling to $2.379 per gallon nationally at the pump. The price is 34.4 cents cheaper than it was in the same week a year ago.

When breaking down prices by region, the largest decrease was in the Midwest, which saw a 2.8-cent drop last week. The smallest change in prices was in the Rocky Mountains, which saw a 0.1-cent decline.

The average price of regular gasoline also fell last week, dropping by 4.8 cents per gallon and settling at $2.182. The price is 56.3 cents cheaper than it was in the same week in 2015.

Mirroring diesel prices, the largest decrease in gas prices was in the Midwest with a 7.4-cent drop week to week. The smallest decrease in prices was in the Rocky Mountain region, falling 1.2 cents last week.

After a surge in energy prices for most of 2016, crude oil prices also appear to be on a slide, closing at a three-month low on July 25, according to a CNBC report. The oil supply glut, which was caused by increasing production and decreasing demand, looks to still be an issue, and the market reflects that it is unlikely to change in the short term.