1982 0.0
1983 6.1
1984 3.5
1985 0.0
1986 0.0
1987 0.0
1988 0.0
1989 0.0
1990 0.0
1991 0.0
1992 2.2
1993 2.2
1994 18.2
1995 3.5
1996 0.2
1997 18.0
1998 6.6
1999 2.2
2000 1.9
2001 5.2
2002 2.4
2003 5.0
2004 3.3
2005 1.6
2006 2.1
2007 7.1
2008 3.3
2009 2.4
2010 2.2
2011 3.1
2012 2.8
2013 5.5
2014 7.8
2015 3.3
2016 2.4
2017 2.4
2018 3.1
2019 18.2
2020 2.4