Gas prices in the United States continue to dip

LOS ANGELES (CNN) -- Gasoline prices continue to drop in the United States, pushed downward by less demand and lower crude oil prices, according to results of a survey released Sunday.

The Lundberg Survey of 10,000 gas stations nationwide showed that prices have dropped nearly a penny a gallon over the last two weeks. Industry analyst Trilby Lundberg said prices were down in all regions of the country.

"It's tough in the oil business," she said. "The national average price is 17 1/2 cents under what it was a year ago."

Lundberg said prices were dropping because of lower crude oil prices and less demand for gasoline at this time of the year.

The weighted average price for all grades of gasoline was just under $1.09 per gallon. The average price of self-serve regular was just under $1.03.

The least expensive gasoline found in the survey was 85.9 cents per gallon for self-service regular in Des Moines, Iowa. The most expensive? In Honolulu, at just more than $1.53 per gallon.