(CNN) -- A 53-cent drop in gas prices over the last two weeks has set another record, and the publisher of a national survey predicted Sunday that prices will continue to decline -- but at a slower pace.

The average price of self-serve, unleaded gas in the United States as of Friday was $2.78 a gallon.

The average price of self-serve, unleaded gas in the United States as of Friday was $2.78 a gallon, compared to $3.31 on October 10, said Trilby Lundberg, publisher of the nationwide Lundberg Survey.

The 35-cent price reduction measured on the 10th, which brought the average price to $3.31, was the largest drop in the six-decade history of the survey, she said.

The all-time high average was $4.11, set on July 11, according to Lundberg, and prices have been dropping ever since.

She attributed the price reductions to crude prices and demand.

"It is those same two factors that will decide what gasoline prices do from here. I think they will probably keep falling, but more slowly," Lundberg said.

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The price of crude oil is the more dominant determinant, she said. Oil Cartel OPEC, the Organization of Petroleum Exporting Countries, said Friday it would cut production by 1.5 million barrels per day starting in November.

Oil prices have fallen by more than half from $147 a barrel in July because of lower demand due to tough economic times, especially in the United States. On Friday, the price of crude closed at $64.15 a barrel, Lundberg said.

"The price of oil doesn't seem likely to jump up substantially any time soon and, considering the U.S. economy, it seems likely that oil prices will stay in their current neighborhood," she said.

The Lundberg Survey is based on responses from more than 5,000 service stations nationwide.

On Friday, Wichita, Kansas, posted the lowest gas price of $2.26 a gallon. The highest prices were in Anchorage, Alaska, $3.50, and Honolulu, $3.48.

Other prices include:

San Francisco, California $3.37

Chicago, Illinois $3.12

Portland, Oregon $2.91

Miami, Florida $2.87

Manchester, New Hampshire $2.79

Philadelphia, Pennsylvania $2.79

Denver, Colorado $2.72

Milwaukee, Wisconsin $2.65

Atlanta, Georgia $2.57

Houston, Texas $2.50

Jackson, Mississippi $2.46

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