Year % 1995 34.93 1996 41.73 1997 34.2 1998 34.32 1999 40.5 2000 36.35 2001 35.13 2002 35.91 2003 35.59 2004 27.69 2005 27.88 2006 34.26 2007 32.86 2008 29.43 2009 27.64 2010 32.58 2011 32.22 2012 33.15 2013 33.41 2014 27.67 2015 31.39 2016 31.02 2017 40.49