The average cost of on-highway diesel continues falling as oil prices hit its lowest level in years, according to new U.S. Energy Department figures.

It has declined another 7 cents from last week to $3.535 per gallon, its lowest level since February 2011. Compared to the same time a year ago the price is 34.4 cents less and compares to a high for the year of $4.021 in March.

Prices once again fell in all regions of the country over the past week, ranging from 4.3 cents in the Central Atlantic states to $3.539, to a much as 9.9 cents in the West Coast region to $3.593. Prices are down by nearly 20 cents to more than 50 cents in the different parts of the country compared to the same time in 2013.

Diesel ranges from a low of $3.386 in the Lower Atlantic states, down 4.3 cents from a week ago, to a high of $3.655 in the Rocky Mountain region, down 7.2 cents over the same time period.

Meantime, the national average cost of regular grade gasoline posted a 9.9 cents drop over the past week, hitting $2.679 per gallon, its lowest level since February 2010. Compared to the same time last year it is 59 cents less.

It ranges from a low of $2.44 in the Gulf Coast region to a high of $2.94 in the West Coast region. Prices are down in all regions over the past week with year-over-year declines of nearly 34 cents to just slightly more than 67 cents in the different parts of the country.

This happened as oil on Monday fell to a five-year low in trading in New York and is about 40% less that its level in July. It settled on Monday at $63.05 per barrel, down $2.79 for the day amid predictions that a global glut of crude will last at least into the first half of 2015, due to increased production in the U.S., continued high production by the OPEC oil cartel and lessening demand by some overseas nations.