Nov 06, 2012 12:57 AM
January 2011: $3.08
February 2011: $3.48
March 2011: $3.57
April 2011: $3.88
May 2011: $3.91
June 2011: $3.65
July 2011: $3.70
August 2011: $3.60
September 2011: $3.66
October 2011: $3.46
November 2011: $3.37
December 2011: $3.23
January 2012: $3.44
February 2012: $3.72
March 2012: $3.93
Source: Consumer Reports