WASHINGTON, D.C. --- The U.S. average retail price for regular gasoline fell 6.8 cents last week to hit $2.31 per gallon as of Oct. 2. That's 61.8 cents lower than a year ago, reported the Energy Department's Energy Information Administration (EIA). Last year during the same period, prices reflected supply disruptions arising from Katrina damage. During the past week, gasoline prices fell for the eighth week in a row, to the lowest national average price since Feb. 27, 2006. East Coast prices fell 8.0 cents to $2.304 per gallon. The Midwest saw prices fall 3.8 cents to $2.169 per gallon, the EIA said. The Rocky Mountains saw the largest regional price decrease, as prices fell 10.5 cents to $2.586 per gallon. West Coast prices were still the highest in the nation after falling 7.4 cents to $2.644 per gallon, the lowest price in that region since March 27, the EIA said. California prices also fell by 7.7 cents to $2.683 per gallon, which is 29.0 cents lower than this time last year. Retail diesel fuel prices fell by 4.9 cents to reach $2.546 per gallon as of Oct. 2, 59.8 cents lower than last year. This is the seventh week in a row that diesel prices have fallen, and the lowest national average price since March 13. Diesel prices declined throughout the country, with the Rocky Mountains seeing the largest regional decrease of 14.8 cents to $2.679 per gallon. West Coast prices, the highest regional prices in the country, dropped 10.3 cents to hit $2.789 per gallon. California prices lost 7.5 cents to reach $2.835 per gallon.