SAN DIEGO, CA — The average price of a gallon of self-serve regular gasoline in San Diego County dropped Tuesday for the fourth consecutive day, decreasing seven-tenths of a cent to $4.021.

The average price has dropped 2.4 cents over the past four days, including two-tenths of a cent on Monday, according to figures from the AAA and Oil Price Information Service.

It is 3.7 cents less than one week ago and 15.4 cents lower than one month ago, but 32.2 cents more than one year ago.