Year | Value | 2021 | 12.049 | 2020 | 12.455 | 2019 | 12.892 | 2018 | 13.307 | 2017 | 13.606 | 2016 | 14.504 | 2015 | 14.641 | 2014 | 15.842 | 2013 | 15.055 | 2012 | 15.094 | 2011 | 14.046 | 2010 | 13.898 | 2009 | 14.255 | 2008 | 13.038 | 2007 | 12.578 | 2006 | 11.759 | 2005 | 13.033 | 2004 | 12.822 | 2003 | 12.482 | 2002 | 12.19 | 2001 | 12.157 | 2000 | 12.51 | 1999 | 13.265 | 1998 | 13.902 | 1997 | 14.75 | 1996 | 15.489 | 1995 | 16.348 | 1994 | 17.465 | 1993 | 18.995 | 1992 | 21.144 | 1991 | 22.95 | 1990 | 24.224 | 1989 | 24.231 | 1988 | 24.657 | 1987 | 25.194 | 1986 | 25.777 | 1985 | 26.4 | 1984 | 26.74 | 1983 | 26.497 | 1982 | 25.821 | 1981 | 25.506 | 1980 | 25.053 | 1979 | 24.73 | 1978 | 24.453 | 1977 | 24.229 | 1976 | 23.725 | 1975 | 23.534 | 1974 | 23.364 | 1973 | 23.251 | 1972 | 23.306 | 1971 | 23.501 | 1970 | 23.704 | 1969 | 24.241 | 1968 | 25.156 | 1967 | 26.078 | 1966 | 27.417 | 1965 | 29.481 | 1964 | 31.821 | 1963 | 34.569 | 1962 | 37.162 | 1961 | 39.38 | 1960 | 40.787 |
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