Year Percent 2000 57.07291 2001 58.05937 2002 59.04451 2003 60.0286 2004 61.01162 2005 61.99456 2006 62.98701 2007 63.97781 2008 64.96746 2009 65.95548 2010 66.9421 2011 67.92733 2012 68.91116 2013 69.8936 2014 70.87444 2015 71.85388 2016 72.83194 2017 72.87482 2018 72.92057 2019 72.9694 2020 73.0211