Year Percent 2000 98.82757 2001 98.80656 2002 98.75599 2003 98.67508 2004 98.59421 2005 98.51336 2006 98.43253 2007 98.35173 2008 98.27096 2009 98.19021 2010 98.10949 2011 98.02879 2012 97.94812 2013 97.86747 2014 97.78685 2015 97.70625 2016 97.62568 2017 97.54514 2018 97.46462 2019 97.38412 2020 97.30366 2021 97.30366 2022 97.30366