Year Percent 2000 87.53536 2001 87.50957 2002 87.92899 2003 88.26265 2004 88.54482 2005 88.82418 2006 89.07559 2007 89.31975 2008 89.56349 2009 89.8144 2010 90.07176 2011 90.32743 2012 90.58126 2013 90.83324 2014 91.08324 2015 91.51934 2016 91.95677 2017 92.39536 2018 92.40346 2019 92.41313 2020 92.42437 2021 92.43718