Diesel and gasoline prices have once again seen a price decrease this past week. Gasoline prices fell 4.5 cents while the price of a gallon of diesel decreased 3.6 cents.

Nationwide, the average price for a gallon of diesel fell barely below the $4-mark to land at $3.99. On the West Coast, the U.S. Energy Information Administration reported, decreases in diesel prices were seen of more than 5 cents per gallon. Prices still sit slightly above $4 on the West Coast at an average of $4.04 per gallon.

In New England and the Central Atlantic regions, diesel prices are higher than the national average at $4.17 per gallon.

Gasoline likewise saw a decrease nationwide this past week, according to the report. The national average for a gallon of gasoline after falling 4.5 cents is $3.35. The Gulf Coast is currently experiencing the lowest gasoline prices at an average of $3.12 a gallon.

Benchmark crude prices also have been falling, and on Monday hit its lowest point since Nov. 15. Prices fell 37 cents to settle at $85.56 per barrel of light, sweet crude oil futures for January.

Reasons behind the falling prices are attributed partly to continued economic uncertainty as well as to falling demand for foreign oil imports as oil output from inside the U.S. increases.