Year Percent 2000 98.80898 2001 98.84723 2002 98.88549 2003 98.92375 2004 98.96201 2005 99.00026 2006 99.03852 2007 99.07678 2008 99.11504 2009 99.08234 2010 98.99992 2011 98.91741 2012 98.8348 2013 98.7521 2014 98.66931 2015 98.65723 2016 98.75353 2017 98.84989 2018 98.94628 2019 99.04272 2020 99.13921 2021 99.1773 2022 99.21539