Year Percent 1996-01-01 98.535500000000000 1997-01-01 94.702900000000000 1998-01-01 94.266000000000000 1999-01-01 91.317400000000000 2000-01-01 90.546500000000000 2001-01-01 87.251000000000000 2002-01-01 80.327900000000000 2003-01-01 74.327600000000000 2004-01-01 72.660400000000000 2005-01-01 68.408300000000000 2006-01-01 68.237100000000000 2007-01-01 62.641800000000000 2008-01-01 60.668100000000000 2009-01-01 58.633999999999990 2010-01-01 59.989200000000000 2011-01-01 56.832500000000000 2012-01-01 56.348600000000000 2013-01-01 56.334300000000000 2014-01-01 59.770900000000000 2015-01-01 63.071999999999996 2016-01-01 64.781200000000000