Year Percent 2000 89.73011 2001 90.02494 2002 90.31555 2003 90.60196 2004 90.88416 2005 91.16215 2006 91.43593 2007 91.70551 2008 91.97088 2009 92.23205 2010 92.489 2011 92.1573 2012 91.8256 2013 91.49389 2014 91.49389 2015 91.49389 2016 91.49389 2017 91.49389