The average retail price of gasoline has taken an unusual downward turn in the past two weeks and could continue to fall slightly through midsummer, said oil industry analyst Dan Lundberg. Lundberg, who conducts a biweekly survey of gasoline prices in all 50 states, said the average price of all grades has dropped 1.55 cents in the past two weeks to an average national price of 95.61 cents per gallon. The drop reflects "an unseasonal decline in price" on the eve of the July 4th holiday. Prices commonly rise in the summer months as consumption increases, he said. Lundberg, publisher of the weekly Lundberg Letter analyzing the oil industry, said wholesale gasoline prices have fallen by 4.7 cents a gallon in the past few days, fueling speculation there will be a further decline in prices at the pumps.