Year % 1991 17.28 1992 17.27 1996 9.17 1999 17.9 2001 6.68 2002 6.57 2003 6.57 2004 6.56 2005 6.59 2006 6.55 2007 5.64 2008 5.63 2010 9.03 2011 9.03 2012 9.03 2013 9.03 2021 5.64