Year % 1993 7.82 1999 14.54 2000 9.52 2001 7.24 2002 7.06 2003 6.99 2004 6.82 2005 6.69 2006 6.82 2007 6.56 2008 6.64 2009 6.63 2011 5.6 2012 5.29 2013 4.69 2014 4.69 2015 4.72 2016 4.57 2017 4.58 2021 3.64