SAN DIEGO - The average price of a gallon of self-serve regular gasoline in San Diego County fell 1 cent Friday to $4.165, decreasing for the 16th consecutive day after rising 28 of the previous 30 days.

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The average price has dropped 12.9 cents over the past 16 days and is 6 cents less than one week ago, 3.5 cents lower than last month and 21.5 cents below what it was one year ago, according to figures from the AAA and Oil Price Information Service.

Prices at the pump have been dropping because most California refineries have concluded scheduled maintenance without experiencing any major incidents before the switch to summer-blend production, leaving adequate gasoline supplies, said Jeffrey Spring of the Automobile Club of Southern California.