Year Percent 2000 37.43666 2001 38.67476 2002 39.91286 2003 41.15096 2004 42.38906 2005 43.62716 2006 45.4632 2007 47.33224 2008 49.23428 2009 51.16932 2010 53.13737 2011 55.13841 2012 57.17246 2013 59.23951 2014 61.33956 2015 63.47261 2016 65.63866 2017 67.83771 2018 70.06977 2019 72.33482 2020 74.63288 2021 76.96394 2022 79.328