WASHINGTON, D.C. --- The downward trend of the past 13 weeks continued as the national average price for regular gasoline slipped 4 cents to $1.659 per gallon, the Energy Information Administration reported on Dec. 17. That's $1.339 below the price a year ago and the lowest price since Feb. 16, 2004.

The price is now $2.455 below the all-time high set on July 7 of this year, the EIA reported. The average price on the East Coast slipped 7.5 cents to $1.682 per gallon. In the Midwest, for the first time in any region since Sept. 15, the average price did not fall. Instead, the price increased 4.2 cents to $1.644 per gallon. The average price in the Gulf Coast fell the most among the major regions, dropping 8.3 cents to $1.556 per gallon, the lowest of any region.

In the Rocky Mountains, the price slipped 6.4 cents to $1.559 per gallon. The price on the West Coast dropped 7.8 cents to $1.751 per gallon. In California, the price slipped 6.7 cents to $1.738 per gallon, the lowest there since the last week of January 2004.