Year % 1991 8.97 1992 12.13 1994 12.37 1995 12.71 1996 12.52 1997 12.52 1998 12.64 1999 12.64 2000 12.64 2001 12.64 2002 12.69 2003 12.68 2004 13.47 2005 13.54 2006 13.67 2007 13.66 2008 13.85 2009 13.77 2010 13.96 2011 11.69 2012 10.36 2013 10.7 2014 10.56 2015 10.53 2016 9.88 2017 11.98 2018 10.25 2019 10.17 2020 10.17 2021 10.17