Year % 1993 7.81 1995 7.3 1996 5.79 1997 5.81 1998 5.74 1999 5.32 2000 5.17 2001 4.2 2002 4.41 2003 4.74 2004 4.37 2005 4.18 2006 4.09 2007 3.98 2008 4.2 2009 4.15 2010 4.2 2011 4.2 2013 4.32 2015 4.31 2016 4.11 2017 4.04 2018 4.01 2019 3.87 2020 4.04 2021 4.18