Year % 1991 15.43 1994 8.77 1995 9.9 1996 11.61 1997 11.79 1998 12.04 1999 10.88 2000 13.59 2001 13.66 2002 13.48 2003 13.54 2004 9.93 2005 8.57 2006 7.31 2007 8.18 2008 8.6 2009 8.1 2010 8.46 2011 8.53 2012 8.48 2013 8.33 2014 8.25 2015 8.22 2016 8.45 2017 8.27 2018 8.3 2019 8.3 2020 7.59 2021 8.25