Year Percent 2000 74.23596 2001 74.41827 2002 74.60059 2003 74.78291 2004 74.96523 2005 75.14755 2006 75.32986 2007 75.83881 2008 76.34933 2009 76.86142 2010 77.3751 2011 77.89035 2012 78.40717 2013 78.92558 2014 79.44556 2015 79.96712 2016 80.49026 2017 81.01497 2018 81.54126 2019 82.06913 2020 82.59858 2021 83.1296 2022 83.6622