1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Note: Percent change is expessed as the difference of the natural logarithm of the current value and the natural logarithm of previous years' values.
Sources: U.S. Bureau of Labor Statistics, U.S. Bureau of Economic Analysis, and U.S. Bureau of Transportation Statistics.