Year % 1991 34.64922 1992 35.39318 1996 40.05213 1999 33.03439 2001 32.38305 2002 33.50002 2003 33.30743 2004 36.34039 2005 35.51476 2006 34.17024 2007 42.01911 2008 41.8508 2010 34.4568 2011 34.4568 2012 34.20491 2013 34.20491 2021 34.64437