Year | Value | 2021 | 8.168 | 2020 | 8.417 | 2019 | 8.465 | 2018 | 8.766 | 2017 | 8.803 | 2016 | 9.092 | 2015 | 9.165 | 2014 | 9.438 | 2013 | 9.537 | 2012 | 9.866 | 2011 | 9.98 | 2010 | 10.326 | 2009 | 10.488 | 2008 | 10.663 | 2007 | 10.775 | 2006 | 10.919 | 2005 | 11.071 | 2004 | 11.304 | 2003 | 11.316 | 2002 | 11.526 | 2001 | 11.8 | 2000 | 11.898 | 1999 | 12.044 | 1998 | 12.258 | 1997 | 12.306 | 1996 | 12.428 | 1995 | 12.537 | 1994 | 12.615 | 1993 | 12.603 | 1992 | 12.617 | 1991 | 12.698 | 1990 | 12.707 | 1989 | 12.761 | 1988 | 12.854 | 1987 | 13.076 | 1986 | 13.319 | 1985 | 13.546 | 1984 | 13.818 | 1983 | 14.158 | 1982 | 14.468 | 1981 | 14.85 | 1980 | 15.259 | 1979 | 15.635 | 1978 | 16.059 | 1977 | 16.443 | 1976 | 16.795 | 1975 | 17.24 | 1974 | 17.711 | 1973 | 18.11 | 1972 | 18.517 | 1971 | 18.923 | 1970 | 19.311 | 1969 | 19.695 | 1968 | 20.028 | 1967 | 20.436 | 1966 | 20.831 | 1965 | 21.185 | 1964 | 21.441 | 1963 | 21.745 | 1962 | 21.951 | 1961 | 22.209 | 1960 | 22.426 |
|