Year Percent 2000 89.65234 2001 90.05271 2002 89.91227 2003 89.76705 2004 89.61703 2005 89.46223 2006 89.30265 2007 89.13827 2008 88.96911 2009 88.79516 2010 88.61642 2011 88.43289 2012 88.24458 2013 88.05148 2014 87.85359 2015 88.22285 2016 88.22285 2017 88.22285 2018 88.22285 2019 88.22285