Maine residents are getting a little relief at the gas pump. Price-monitoring website MaineGasPrices.com reports Monday that the average retail cost of a gallon of gas has fallen more than a penny in the past week to $3.56. Prices also fell a little more than a penny nationally, but the national average remains much higher at $3.64. Maine prices are now 7 cents lower than at the same time last year, but 7 cents higher per gallon than a month ago. The Maine average is based on a survey of more than 1,200 gas stations across the state.