WASHINGTON, D.C. --- For the third straight week, gasoline prices were up, increasing 4.9 cents to an average of $3.103 per gallon as of May 14. Prices were 15.6 cents per gallon higher than this time last year and reached an all-time nominal high, the Energy Department's Energy Information Administration reported. All regions reported price increases. East Coast prices were up 2.3 cents to $2.981 per gallon. In the Midwest, prices jumped 9.8 cents to $3.172 per gallon, while prices for the Gulf Coast rose 4.5 cents to $2.915 per gallon. The largest increase was in the Rocky Mountains, where prices rose 10.3 cents to $3.193 per gallon. West Coast prices were up 0.5 cent to $3.378 per gallon. The average price for regular grade in California was down 1.1 cents to $3.450 per gallon, but remained 12.0 cents per gallon above last year's price. Retail diesel prices fell for the fourth consecutive week, decreasing 1.9 cents to $2.773 per gallon. Diesel prices were 14.7 cents per gallon lower than at this time last year. East Coast diesel prices fell 2.3 cents to $2.758 per gallon. In the Midwest, diesel prices were down 1.4 cents to $2.740 per gallon, while the Gulf Coast saw a decrease of 3.1 cents to $2.713 per gallon. The only region to see an increase in diesel prices was the Rocky Mountains, where prices rose 0.3 cent to $2.998 per gallon. Diesel prices on the West Coast saw a decrease of 1.6 cents to $2.919 per gallon. California prices fell 2.2 cents to $2.952 per gallon, 29.0 cents per gallon lower than at this time last year.