The average price of on-highway diesel fuel moved lower over the past week, after seeing its first increase since June last week, according to the U.S. Energy Department’s weekly report on Monday.

It fell 1.6 cents this week to $3.661 per gallon, one of the lowest prices so far this year. Compared to the same time last year the average price is 16.1 cents less.

Regionally, all prices declined over the past week, except for the West Coast minus California, where it added 0.8 cents for an average of $3.72 per gallon. Prices fell between 0.2 cent in the Midwest to as much as 4.4 cents in California. The Midwest also had the distinction of having the highest price of any region at $3.786, though the average cost for the state of California was slightly more at $3.797.

The least expensive regional price is in the Gulf Coast region, down 2 cents from last week, for an average of $3.542.

The average cost of regular grade gasoline also declined over the past week, giving up 4.7 cents and hitting $3.894. The current price is 32.5 cents less than the same time last year.

All regions posted drops over the past week and it ranges from a low of $3.673 in the Gulf Coast region to a high of $3.114 in the West Coast region. Before the one-week hike last week diesel declined 30 cents from June, hitting its lowest level since February 2011.

Also on Monday, the cost of oil fell 18 cents at the close of trading in New York, settling at $75.64 per barrel. This was triggered by news that the Japanese economy slipped back into a recession and skepticism that the OPEC oil cartel will soon put together a deal to put an end to sliding crude prices. Compared to last Tuesday’s opening, the price oil is down about $1.50 in New York trading.