Year Percent 1991 75.556 1992 64.532 1993 63.656 1994 67.798 1995 64.557 1996 72.034 1997 72.149 1998 68.471 1999 71.761 2000 69.561 2001 69.445 2002 70.888 2003 70.807 2004 69.938 2005 78.513 2006 80.275 2007 79.555 2008 74.538 2009 71.103 2010 71.624 2011 71.427 2012 71.059 2013 70.85 2014 71.5 2015 72.642 2016 72.723 2017 75.551 2018 76.483 2019 77.123 2020 76.946 2021 77.042 2022 77.053