Year Percent 2003-01-01 3.83517527298986 2004-01-01 4.01538736681159 2005-01-01 4.02535895424465 2006-01-01 4.04182159260319 2007-01-01 3.73264698387038 2008-01-01 3.44717922029439 2009-01-01 4.44834066569493 2010-01-01 4.45425755158764 2011-01-01 4.32430569962853 2012-01-01 4.82275566377647 2013-01-01 4.92662111950762