Year Percent 1996-01-01 71.8795 1997-01-01 73.0703 1998-01-01 71.5054 1999-01-01 42.4609 2000-01-01 46.5454 2001-01-01 50.2164 2002-01-01 50.4228 2003-01-01 48.1823 2004-01-01 82.7230 2005-01-01 69.7447 2006-01-01 70.3820 2007-01-01 76.7563 2008-01-01 79.0800 2009-01-01 75.0557 2010-01-01 75.6614 2011-01-01 75.7661 2012-01-01 74.4707 2013-01-01 73.3877 2014-01-01 73.4064 2015-01-01 71.0253 2016-01-01 70.3001