Year | Value | 2021 | 1.692 | 2020 | 1.708 | 2019 | 1.77 | 2018 | 1.968 | 2017 | 2.074 | 2016 | 2.07 | 2015 | 2.053 | 2014 | 2.036 | 2013 | 1.961 | 2012 | 1.886 | 2011 | 1.8 | 2010 | 1.768 | 2009 | 1.766 | 2008 | 1.767 | 2007 | 1.768 | 2006 | 1.771 | 2005 | 1.775 | 2004 | 1.796 | 2003 | 1.824 | 2002 | 1.865 | 2001 | 1.94 | 2000 | 2.016 | 1999 | 2.099 | 1998 | 2.197 | 1997 | 2.333 | 1996 | 2.566 | 1995 | 2.885 | 1994 | 3.271 | 1993 | 3.683 | 1992 | 4.082 | 1991 | 4.506 | 1990 | 4.863 | 1989 | 5.108 | 1988 | 5.387 | 1987 | 5.69 | 1986 | 6.012 | 1985 | 6.264 | 1984 | 6.436 | 1983 | 6.511 | 1982 | 6.554 | 1981 | 6.558 | 1980 | 6.584 | 1979 | 6.531 | 1978 | 6.332 | 1977 | 6.203 | 1976 | 6.136 | 1975 | 6.008 | 1974 | 6.042 | 1973 | 6.106 | 1972 | 6.25 | 1971 | 6.51 | 1970 | 6.707 | 1969 | 6.899 | 1968 | 6.974 | 1967 | 7.051 | 1966 | 7.075 | 1965 | 7.106 | 1964 | 7.131 | 1963 | 7.181 | 1962 | 7.224 | 1961 | 7.227 | 1960 | 7.301 |
|