Year Percent 2001 85.86436 2002 86.02958 2003 86.1932 2004 86.35523 2005 86.51533 2006 86.66102 2007 86.6801 2008 86.27042 2009 85.85379 2010 85.43103 2011 85.00233 2012 84.56643 2013 84.12303 2014 83.67295 2015 83.21614 2016 82.75312 2017 82.28384 2018 81.80905 2019 81.32845 2020 81.37833 2021 81.42211 2022 81.45967