Year % 1989 3.91 1990 3.92 1991 3.95 1992 3.95 1993 3.75 1995 2.94 1996 2.86 1997 2.6 1998 3.09 1999 2.31 2000 2.1 2001 2.11 2002 2.16 2003 1.96 2004 1.79 2005 1.75 2006 1.7 2007 1.55 2008 1.58 2009 1.71 2010 1.66 2011 1.67 2012 1.67 2013 1.67 2014 1.69 2015 1.69 2016 1.65 2017 1.66 2018 1.59 2019 13.78 2020 1.52 2021 1.47