Year % 1989 6.39 1990 6.39 1991 6.37 1992 6.39 1993 6.4 1995 5.73 1996 5.42 1997 5.19 1998 4.71 1999 4.34 2000 4.31 2001 4.19 2002 4.1 2003 3.96 2004 3.82 2005 3.8 2006 3.79 2007 3.65 2008 3.84 2009 3.88 2010 3.9 2011 3.89 2012 3.79 2013 3.78 2014 3.77 2015 3.78 2016 3.78 2017 3.53 2018 3.76 2019 4.15 2020 3.7 2021 3.79