Year % 1994 14.6 1997 15.21 2001 11.35 2002 11.35 2003 11.25 2004 11.25 2005 11.4 2006 11.25 2007 15.74 2008 15.72 2009 15.72 2010 15.72 2011 15.72 2013 15.8 2014 15.74 2015 10.23