Since 1980, the traditional Japanese manufacturers have increased their combined fleet average fuel economy by 1.6 miles per gallon according to the March 30, 2009 Summary of Fuel Economy Performance published annually by NHTSA. During this time, they also increased their sales in the United States by 221%. The traditional European manufacturers actually decreased their fleet average fuel economy by 2 miles per gallon while increasing their sales volume by 91%. The traditional U.S. manufacturers, Chrysler, Ford, and General Motors, increased their fleet average fuel economy by 4.1 miles per gallon since 1980 according to the latest government figures. During this time the sales of U.S. manufacturers decreased by 29%.