The average price of diesel fuel jumped again, increasing for the seventh week in a row, according to the latest numbers from the Energy Department.

The price of on-highway diesel fuel increased by an average 6 cents last week, bringing the average per-gallon price to $2.357. The price is still 55.7 cents cheaper than it was in the same week a year ago.

Prices were up across the board by region, with the largest increased coming to the Gulf Coast at 7.6 cents for the week. The smallest increase in prices was in the Rocky Mountain region at 3.4 cents.

The price of regular gasoline was up by a similar amount for the week with a 5.8-cent increase to $2.30 per gallon. Despite rising prices for the past few months, the price is 47.4 cents cheaper than it was a year ago.

The largest increase in prices by region was in the Midwest at 10 cents per gallon. The smallest increase in prices was in the West Coast at 1.4 cents per gallon.

While crude oil prices have trended toward higher prices so far this year, week to week the prices have been up and down based on reports and speculation about the global supply. On May 23, the price ended lower than the previous week on renewed expectations that the global oil supply is outpacing demand, according to a MarketWatch report.

While just last week analysts were pointing to new numbers showing that supply was no longer significantly higher than demand, many of the factors that led to a reduction in oil production were seen as temporary. These factors included the wildfires in Canada and a worker strike in the Middle East.