200 -- amount of terawatt-hours saved annually by the gradual switch to more efficient refrigerators in the USA (see chart above).
80 -- roughly the number of extra power plants that the USA would need without these efficiency improvements.
7 -- that's the percentage of GDP that is spent on energy in the USA. Energy intensity per unit of GDP has been decreasing about about 2% per year in the USA, and about 1.5% per year overall on the planet.
The source of these numbers and more can be found in this very interesting article about energy efficiency: ::The elusive negawatt