Year Percent 2000 99.68321 2001 99.687 2002 99.68935 2003 99.65066 2004 99.59544 2005 99.5404 2006 99.48554 2007 99.43086 2008 99.37636 2009 99.32204 2010 99.26791 2011 99.21396 2012 99.16029 2013 99.10659 2014 99.05268 2015 99.05797 2016 99.06308 2017 99.06799 2018 99.07268 2019 99.07716 2020 99.08075 2021 99.07053 2022 99.06022