Year Percent 2000 91.08965 2001 91.02869 2002 90.96773 2003 90.90677 2004 90.84581 2005 90.78485 2006 90.72389 2007 90.66293 2008 90.60197 2009 90.54101 2010 90.48005 2011 90.41909 2012 90.35813 2013 90.29717 2014 90.23621 2015 90.17525 2016 90.11429 2017 90.11429 2018 90.11429 2019 90.11429 2020 90.11429