Year Percent 2000 99.86668 2001 99.86884 2002 99.86934 2003 99.86986 2004 99.87036 2005 99.86396 2006 99.84301 2007 99.76076 2008 99.67827 2009 99.59556 2010 99.51262 2011 99.42938 2012 99.34555 2013 99.26168 2014 99.17775 2015 99.09378 2016 99.00975 2017 98.92568 2018 98.84154 2019 98.75733 2020 98.67301 2021 98.58857 2022 98.58836