Year Percent 2000 78.68496 2001 78.73919 2002 78.79454 2003 78.851 2004 78.90859 2005 78.1098 2006 77.15286 2007 76.21346 2008 75.29205 2009 74.3885 2010 73.50322 2011 72.63483 2012 71.78353 2013 70.94907 2014 70.13113 2015 69.32992 2016 68.5448 2017 67.77596 2018 67.00626 2019 67.1538 2020 67.30103 2021 67.44761