RIVERSIDE, Calif. -

 The average price of a gallon of self-serve regular  gasoline in the Inland Empire rose to its highest amount since Sept. 30 Monday, increasing three-tenths of a cent to $3.91.

   The average price in Riverside and San Bernardino counties has risen 27 of the past 28 days and is 6.6 cents more than one week ago and 31.4 cents higher than one month ago, but 36.2 cents less than one year ago, according to figures from the AAA and Oil Price Information Service.

   The average price has risen 30.4 cents over the past 28 days, including 1 cent on both Saturday and Sunday.