Year | Value | 2022 | 16.916 | 2021 | 17.127 | 2020 | 17.336 | 2019 | 17.541 | 2018 | 17.744 | 2017 | 17.942 | 2016 | 18.138 | 2015 | 18.329 | 2014 | 18.517 | 2013 | 18.701 | 2012 | 18.881 | 2011 | 19.056 | 2010 | 19.228 | 2009 | 19.394 | 2008 | 19.562 | 2007 | 19.731 | 2006 | 19.901 | 2005 | 20.072 | 2004 | 20.243 | 2003 | 20.417 | 2002 | 20.591 | 2001 | 20.766 | 2000 | 20.943 | 1999 | 21.258 | 1998 | 21.623 | 1997 | 21.992 | 1996 | 22.364 | 1995 | 22.743 | 1994 | 23.125 | 1993 | 23.512 | 1992 | 23.903 | 1991 | 24.299 | 1990 | 24.7 | 1989 | 24.911 | 1988 | 25.058 | 1987 | 25.207 | 1986 | 25.356 | 1985 | 25.506 | 1984 | 25.656 | 1983 | 25.806 | 1982 | 25.958 | 1981 | 26.11 | 1980 | 26.262 | 1979 | 26.308 | 1978 | 26.318 | 1977 | 26.327 | 1976 | 26.337 | 1975 | 26.347 | 1974 | 26.357 | 1973 | 26.367 | 1972 | 26.377 | 1971 | 26.387 | 1970 | 26.398 | 1969 | 26.667 | 1968 | 27.026 | 1967 | 27.388 | 1966 | 27.753 | 1965 | 28.121 | 1964 | 28.492 | 1963 | 28.866 | 1962 | 29.243 | 1961 | 29.623 | 1960 | 30.004 |
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