Survey based on prices as of April 1, 2005 ...
and wonders why they went back 2 years and 4 months for their data.
(I originally used it in a diary that balsted the Economist for claiming - in the very article where that graph was published - that "of course the British liberalised system was superior because it delivered cheaper prices"...) In the long run, we're all dead. John Maynard Keynes