The simple energy consumption/GDP (E/GDP) ratio measure of energy intensity overstates the extent to which energy efficiency improvements have occurred in the economy. We are using significantly less energy because heavy industry has gone elsewhere.
A shift from this heavy manufacturing to service oriented industries influences the simple E/GDP ratio, but is not indicative of improvements in energy efficiency.
In 2008 the DOE developed a better measure based on ratios of energy efficiency based on energy intensity by sector. It seems the EIA has shifted their position-and now claim "2011 was the most economically energy-efficient year on record, ever" based on the E/GDP ratio. I don't think so.