Year % 1993 29.36 1997 17.34 2001 28.1 2002 25.22 2003 13.72 2004 32.66 2005 14.87 2006 30.31 2007 23.94 2008 13.12 2009 9.25 2010 9.27 2011 8.41 2012 11.24 2013 11.69 2015 11.68 2016 13.33 2018 12.95 2020 12.97 2021 13.33