Gasoline prices dataset. The graph elaborates on $3.785/per gallon. However, the median and average price for all dataseries= $1.81 Average, Median $ 1.31. In December 2008 Gasoline prices were $ 1.69, converging to the median estimated historical price.
for instance Sigma Chart of Gasoline prices. Peaked 73.2% yearly Standard Deviation 2008. We can observe that Gasoline prices could produce again a 73,2% sigma, before decreasing to $1.69 dollar per gallon.