Army and Air Force Exchange Service fuel prices will plunge at least 13.7 cents a gallon Saturday in Germany, the United Kingdom and the Netherlands, after U.S. prices declined for a third straight week.

For the first time since January, prices on all grades of gas in the Netherlands fall below $4 a gallon. As a result of the plunge, gas prices in the country won’t be at so-called floor prices — prices at which the exchange sells fuel at cost — for the first time in more than a year.

In Germany, the price of regular is down 14.8 cents a gallon, while midgrade and premium blends are down 13.7 cents in both Germany and the U.K. [See page 14 for a rundown of prices.]

The slowdown in economic growth is contributing to the decline in both demand and prices for oil, according to a monthly energy report issued Tuesday by the U.S. Energy Information Administration. The EIA lowered its forecast on the price of West Texas Intermediate crude oil for the coming year, and suggested prices — including prices at the pump — could fall further if a major worldwide economic downturn affects demand.

In August, the cost of crude oil made up 73 percent of the price of a gallon of gasoline in the U.S., according to the EIA.