In 2007, fuel stations sold 22.872 billion litres of petrol and 14.800 billion litres of diesel, totalling 37.672 billion litres.
Last year, according to latest Department of Energy and Climate Change figures, retailers sold 17.426 billion litres of petrol and 16.734 billion litres of diesel, totalling 34.160 billion litres.
Despite bigger sales of diesel over the past five years, some of it due to companies now buying the fuel direct from forecourts instead of storing it in depots, total fuel sales have fallen 9.3% in the past five years.
Edmund King, president of insurer AA, said: "Greater take-up of diesel cars and smaller petrol vehicles has contributed to this overall decline in UK fuel sales over the long term.
"However, soaring pump prices have taken a huge toll on petrol sales more recently - during the 10p-a-litre price surges last March and October, pump sales of petrol fell by up to 5%.
"The trouble is that, with global economic recovery, the stock market will predict greater oil and fuel demand and push up commodity values accordingly.
"Drivers' fuel consumption and retail survivability are already precarious, what will happen when the speculators pump themselves up with bullish sentiment and send prices soaring yet again?"
This report comes at a time when households are having to fork out a bulk of their monthly income on petrol and transport costs.
According to Santander, the cost of filling up the average family car with a 70-litre tank is now £97.37 - a 5.5% increase in just two months.
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