Year % 1989 4.2 1990 4.22 1991 4.25 1992 4.25 1993 4.09 1995 3.11 1996 2.95 1997 2.83 1998 3.09 1999 2.12 2000 2.06 2001 2.13 2002 2.21 2003 2.08 2004 1.91 2005 1.87 2006 1.84 2007 1.64 2008 1.78 2009 1.84 2010 1.81 2011 1.79 2012 1.75 2013 1.75 2014 1.75 2015 1.74 2016 1.68 2017 1.57 2018 1.58 2019 2.19 2020 1.55 2021 1.57