Year Percent 2000 49.5978 2001 52.3871 2002 55.0503 2003 56.939 2004 50.5358 2005 49.9731 2006 48.6637 2007 46.9919 2008 41.7228 2009 45.0927 2010 48.1012 2011 46.2548 2012 47.636 2013 47.9778 2014 48.0218 2015 46.3429 2016 48.6184 2017 49.3051