WASHINGTON, D.C. --- The U.S. average retail price for regular gasoline fell 7.6 cents last week to hit $2.924 per gallon as of Aug. 21. That's 31.2 cents higher than last year, according to the Energy Department's Energy Information Administration (EIA). Prices fell for the second week in a row, dropping below the $3 mark for the first time in five weeks. East Coast prices lost 7.5 cents to hit $2.933 per gallon. The Midwest saw the largest regional price decrease of 11.1 cents to $2.861 per gallon. West Coast prices, the highest in the nation, fell 3.9 cents to $3.098 per gallon. California prices were 4.9 cents lower at $3.162 per gallon. Retail diesel fuel prices declined 3.2 cents to reach $3.033 per gallon as of Aug. 21. That's 44.5 cents higher than last year and the third week in a row that prices have been over the $3 mark. Prices varied throughout the country, with the Rocky Mountains seeing the largest regional increase of 3.8 cents to $3.349 per gallon, the highest regional price in the country. East Coast prices fell by 7.4 cents to $2.953 per gallon.