Retail Gasoline Prices in 2014 Experienced the Largest Decline since 2008
February 2, 2015
In the second half of 2014, the national average retail price per gallon of gasoline (all grades) fell from a high of $3.77 in June to a low of $2.63 in December – a difference of $1.14 per gallon. This is the largest price drop since the recession of 2008 where a loss of demand led to collapsing fuel prices. The price of gasoline is highly volatile and often varies substantially throughout any given year. The year 2010 is an exception with a modest price variation and gasoline prices remaining under $3.00 per gallon for almost the entire year.
Retail Gasoline Price Changes, 2008–2014

Source
Energy Information Administration, U.S. All Grades All Formulations Retail Gasoline Prices (Dollars per Gallon), accessed 01/22/2015.