Year Percent 1995 55.03863 1996 56.438 1997 56.49226 1998 58.25696 1999 62.07026 2000 60.17772 2001 59.63862 2002 59.62987 2003 59.51873 2004 59.57247 2005 59.08319 2006 58.26118 2007 57.67717 2008 60.38509 2009 61.30979 2010 60.2189 2011 58.69075 2012 59.08258 2013 59.45759 2014 59.05149 2015 59.8093 2016 60.54824 2017 60.362