Year % 1991 14.5 1994 8.15 1995 10.4 1996 9.42 1997 9.9 1998 10.24 1999 10.5 2000 11.73 2001 11.94 2002 11.34 2003 11.55 2004 11.72 2005 9.5 2006 5.41 2007 6.92 2008 7.25 2009 7.26 2010 7.51 2011 7.98 2012 8.18 2013 8.32 2014 8.12 2015 8.49 2016 8.14 2017 7.97 2018 8.05 2019 8.05 2020 7.39 2021 7.59