Year Percent 1996-01-01 28.9588 1997-01-01 23.2743 1998-01-01 25.6807 1999-01-01 32.0975 2000-01-01 26.7995 2001-01-01 33.0880 2002-01-01 31.8455 2003-01-01 36.9596 2004-01-01 26.3348 2005-01-01 23.5693 2006-01-01 27.1448 2007-01-01 25.8803 2008-01-01 22.9592 2009-01-01 39.4754 2010-01-01 27.3420 2011-01-01 20.2074 2012-01-01 32.4721 2013-01-01 28.7769 2014-01-01 28.4577