WASHINGTON, D.C. --- The U.S. average retail price for regular gasoline for Jan. 15 decreased 7.7 cents to $2.229 per gallon, according to the weekly report released by the Energy Department's Energy Information Administration (EIA). Prices are now 9.1 cents per gallon lower than at this time last year. East Coast prices fell 5.7 cents to $2.262 per gallon. For the second consecutive week, the Midwest saw the largest regional decrease, with prices falling 13.3 cents to $2.077 per gallon. Prices there are now 18.6 cents per gallon lower than at this time last year, the EIA said. Gulf Coast prices were down 6.0 cents to $2.111 per gallon, while Rocky Mountain prices fell 3.5 cents to $2.199 per gallon. Prices for the West Coast were down 4.0 cents to $2.554 per gallon, but remain 18.2 cents per gallon higher than at this time last year. Retail diesel fuel prices also continued to fall, decreasing 7.4 cents to $2.463 per gallon. Prices are 1.4 cents higher than at this time last year. East Coast prices saw the largest regional decrease, falling 8.3 cents to $2.437 per gallon. Midwest diesel prices dropped 7.5 cents to $2.408 per gallon. The Gulf Coast saw a decrease of 6.8 cents to $2.391 per gallon. Rocky Mountain diesel prices fell 5.7 cents to $2.625 per gallon, and prices on the West Coast decreased 7.5 cents to $2.749 per gallon, the EIA reported.