Year Percent 2000 64.10405 2001 64.88412 2002 65.65336 2003 66.41234 2004 67.16079 2005 67.89846 2006 68.62632 2007 69.34373 2008 70.00359 2009 70.63616 2010 71.26425 2011 71.88718 2012 72.50571 2013 73.11919 2014 73.72803 2015 74.33255 2016 74.93221 2017 75.52734 2018 76.11989 2019 76.70944 2020 77.2961 2021 77.87949 2022 78.45946