Maine gas prices continue to trickle down, but aren’t falling as fast as they are nationally. Price-monitoring website MaineGasPrices.com reports Monday that the average retail cost of a gallon of gas in Maine dropped by a little more than three cents in the past week, to an average of $3.53. Nationally, prices dropped by more than a nickel in the past week to an average of $3.34 per gallon. Maine prices are now six cents lower than a month ago, yet remain 15 cents higher than at the same time last year. A company analyst says he’s expecting prices to continue to fall.