Year Percent 2000 97.9731 2001 98.01251 2002 98.05191 2003 98.09132 2004 98.13072 2005 98.17013 2006 98.20953 2007 98.24893 2008 98.28834 2009 98.32774 2010 98.36715 2011 98.40655 2012 98.44596 2013 98.48536 2014 98.52477 2015 98.56417 2016 98.60358 2017 98.64298 2018 98.68238 2019 98.72179 2020 98.76119 2021 98.8006 2022 98.84