Year % 1995 15.48 1997 20.88 2001 22.51 2002 19.76 2003 29.88 2004 29.88 2005 29.24 2006 29.89 2007 22.63 2008 22.63 2009 22.63 2010 22.63 2011 22.91 2012 21.91 2013 20.89 2015 20.22 2016 20.22 2017 20.22