Year Percent 1996-01-01 34.3304 1997-01-01 31.6968 1998-01-01 34.7640 1999-01-01 28.3437 2000-01-01 31.6872 2001-01-01 29.3438 2002-01-01 27.3278 2003-01-01 37.5477 2004-01-01 35.1023 2005-01-01 40.2998 2006-01-01 33.1063 2007-01-01 30.6827 2008-01-01 32.0335 2009-01-01 27.4858 2010-01-01 24.9367 2011-01-01 24.8607 2012-01-01 24.1551 2013-01-01 24.2742 2014-01-01 25.3828 2015-01-01 29.6553 2016-01-01 25.2893