The average price of a gallon of self-serve regular gasoline in the Inland Empire dropped nine-tenths of a cent Monday to $4.09, its lowest amount since April 8.

   The average price in Riverside and San Bernardino counties is 1.8 cents less than one week ago, and 8.1 cents lower than one month ago, but 10.9 cents more than one year ago, according to figures from the AAA and Oil Price Information Service.

   Over the past 10 days, the average price dropped six times, rose three times and was unchanged once.