Year Percent 2000 51.00842 2001 53.84508 2002 56.68174 2003 59.5184 2004 62.35506 2005 65.35975 2006 68.37905 2007 71.41299 2008 74.46154 2009 77.52472 2010 80.60252 2011 83.69494 2012 86.80198 2013 89.92365 2014 92.82611 2015 95.72857 2016 95.72857 2017 95.72857 2018 95.72857 2019 95.72857