Year Percent 1995 66.42883 1996 66.98606 1997 68.66488 1998 69.30238 1999 70.23456 2000 69.78296 2001 69.33525 2002 68.40354 2003 67.35553 2004 66.82427 2005 66.73693 2006 66.99234 2007 66.09914 2008 66.38167 2009 69.98474 2010 71.25832 2011 73.91225 2012 75.35314 2013 76.92125 2014 76.53571 2015 76.26536 2016 75.71614