Year % 1996 27.33 1999 22.49 2000 21.64 2001 14.84 2002 14.35 2003 14.94 2004 14.47 2006 15.78 2007 14 2010 13.35 2011 13.82 2012 14.13 2013 13.44 2020 9.67 2021 9.99