Year Percent 2000 68.87749 2001 69.8047 2002 70.73191 2003 71.65912 2004 72.21758 2005 72.76661 2006 73.30623 2007 73.83642 2008 74.35719 2009 74.86855 2010 75.37048 2011 75.86299 2012 76.34608 2013 76.81975 2014 77.284 2015 77.73883 2016 78.18424 2017 78.62022 2018 79.04679 2019 79.46394 2020 79.87166 2021 80.26997 2022 81.11239