Year % 1988 6.9 1989 7 1990 7.36 1991 7.27 1992 7.33 1993 7.13 1994 7.27 1995 17.54 1996 16.3 1997 15.76 1998 14.19 1999 14.06 2000 12 2001 13.08 2002 10.97 2003 11.18 2004 11.34 2005 11.98 2006 11.87 2007 10.85 2008 10.4 2009 10.3 2010 10.37 2011 10.39 2012 10.42 2013 10.24 2014 10.26 2015 10.28 2016 10.31 2017 10.03 2018 9.99 2019 12.26 2020 5.58 2021 10.21