Year Percent 2000 81.93204 2001 82.04798 2002 82.16393 2003 82.27987 2004 82.39582 2005 82.51177 2006 82.62771 2007 82.74366 2008 82.85961 2009 82.97555 2010 83.0915 2011 83.20744 2012 83.32339 2013 83.43934 2014 83.55528 2015 83.67123 2016 83.78718 2017 83.90312 2018 84.01907 2019 84.13501 2020 84.13501 2021 84.13501 2022 84.13501