RIVERSIDE, Calif. -

The average price of a gallon of self-serve regular gasoline in the Inland Empire dropped Sunday for the 12th consecutive day, and stood at $4.05.

   The average price in Riverside and San Bernardino counties has decreased two-tenths of a cent overnight, and decreased 9.8 cents over the past 12 days, according to figures from the AAA and Oil Price Information Service.  Sunday's price was down 1.3 cents overnight.

   The average price is 5.6 cents less than one week ago, 4.3 cents lower than one month ago and 2.2 cents below what it was one year ago.

   The streak of decreases was immediately preceded by 11 increases in 14 days that pushed the average price to its highest amount since May 19.

   The dropping pump prices stem from continuing decreases to the wholesale price caused by an improving supply situation, according to Jeffrey Spring of the Automobile Club of Southern California.