Year % 1991 26.14 1992 27.95 1996 18.23 1999 28.03 2001 17.97 2002 15.05 2003 15.59 2004 19.73 2005 18.91 2006 17.19 2007 17.13 2008 17.09 2010 20.09 2011 20.1 2012 17.69 2013 17.4 2021 24.25