The average price of a gallon of on-highway diesel fuel was down for the 11th straight week according to the latest numbers from the U.S. Energy Department.

The price of diesel dropped 5.1 cents nationally to an average price of $2.617 per gallon. The price is down $1.226 per gallon from the same week a year ago.

The largest drop in prices regionally was in California, for a change, falling by 6.4 cents to a still nation-leading $2.96 per gallon average. The smallest drop in prices was in the Rocky Mountain region, dropping 4.5 cents to an average price of $2.64 per gallon.

Gasoline prices followed suit, dropping nationally by 6 cents per gallon to an average price of $2.629. The largest decrease in prices was in the West Coast region, dropping 11.9 cents to $3.361 per gallon. The smallest drop was in the Rocky Mountain region, falling 3 cents to $2.798 per gallon.

Crude oil was up slightly Monday, ending a three-day losing streak, according a Market Watch report. Despite the slight rebound, analysts are cautious about per barrel oil prices in the near future thanks to a glut of oil supply globally and a weakening demand in places like China.