The price of gasoline is shown at a filling station in San Francisco, California July 1, 2008. U.S. retail gasoline demand remained in a slump as high prices at the pump trimmed demand for the fuel, while the national average price of gasoline dipped 1 cent last week, but at $4.06 per gallon was more than 36 percent higher than this time last year. REUTERS/Robert Galbraith (UNITED STATES)