WASHINGTON, D.C. --- The U.S. average retail price for regular gasoline dipped 2.5 cents last week to $2.867 per gallon as of May 29, according to the Energy Department. That's 77 cents higher than last year. This is the second straight week that prices have dropped, reported the Energy Department's Energy Information Administration (EIA). Though most of the country saw price decreases, that wasn't the case in the Midwest. Prices rose in that region by 0.3 cent to reach an average of $2.76 per gallon. The Gulf Coast saw the largest price decrease, falling 4.6 cents to $2.737 per gallon, the EIA reported. West Coast prices remained the highest in the nation, falling 4.4 cents to $3.205 per gallon. California prices fell 5.7 cents to $3.266 per gallon. The East Coast saw a price decrease of 3.4 cents to $2.859 per gallon. Retail diesel fuel prices fell 0.6 cent to reach $2.882 per gallon as of May 29, which is 72.2 cents higher than last year. Prices were mostly down throughout the country. The Rocky Mountains, however, saw an increase of 2 cents to reach $3.044 per gallon, the EIA said. West Coast prices remained the highest in the country, falling 1.4 cents to $3.161 per gallon, while California prices edged down 0.7 cent to $3.227 per gallon. East Coast prices fell 0.4 cent to $2.873 per gallon.