WASHINGTON, D.C. --- The U.S. average retail price for regular gasoline dropped by 4.7 cents to 215.4 cents per gallon, falling for the eighth week in a row, reported the Energy Department's Energy Information Administration (EIA). This price was the lowest since June 13, 2005, but still is 20.9 cents higher than this time last year. Retail prices have fallen by more than 77 cents per gallon in the past eight weeks, according to the EIA. Although prices fell nationwide, the Rocky Mountains saw the largest decrease of 7.0 cents to 218.2 cents per gallon. The Midwest had the lowest regional price after falling 3.3 cents to 205.4 cents per gallon. West Coast prices fell 4.4 cents to 238.9 cents per gallon, the highest regional price in the country. California prices fell 4.1 cents to 241.2 cents per gallon. East Coast prices fell by 5.4 cents to 215.2 cents per gallon, the EIA reported. Retail diesel fuel prices fell 3.4 cents to 247.9 cents per gallon, the lowest price since August 8, 2005. The U.S. average retail diesel price has fallen almost 68 cents per gallon during the past five weeks. Diesel prices were down throughout the country, with the Rocky Mountains seeing the largest regional decrease of 6.3 cents to 259.1 cents per gallon. Midwest prices were down 3.5 cents to 244.2 cents per gallon, the lowest regional price in the nation. West Coast prices, the highest in the country, averaged 261.7 cents per gallon after falling 3.5 cents, according to the EIA.