Year Percent 1982 3.4 1983 3.8 1984 5.84 1985 6.92 1986 8.29 1987 7.33 1988 7.26 1989 5.73 1990 4.5 1992 3.71 1993 4.11 1995 3.15 1996 2.52 1997 2.45 1998 3.2 1999 3.43 2000 3 2001 3.53 2002 3.48 2003 3.61 2004 3.54 2005 3.53 2006 3.31 2007 3.23 2008 3.32 2009 3.66 2010 3.39 2011 3.05 2012 3.1 2013 3.16 2014 2.88 2015 3.1 2016 3.44 2017 3.41 2018 3.3 2019 3.26 2020 4.54