Year % 1995 60.1 1996 49.62 1997 42.24 1998 62.44 1999 64.72 2000 51.79 2001 51.79 2002 55.29 2003 51.92 2004 45.79 2005 45.79 2006 45.78 2007 48.84 2008 45.74 2009 45.75 2010 45.75 2011 46.17 2012 46.95 2013 48.44 2014 40.06 2015 46.95 2016 48.55 2017 31.72