Year | Value | 2022 | 14.538 | 2021 | 14.471 | 2020 | 14.416 | 2019 | 14.371 | 2018 | 14.338 | 2017 | 14.315 | 2016 | 14.303 | 2015 | 14.303 | 2014 | 14.313 | 2013 | 14.334 | 2012 | 14.367 | 2011 | 14.41 | 2010 | 14.464 | 2009 | 14.519 | 2008 | 14.574 | 2007 | 14.629 | 2006 | 14.684 | 2005 | 14.739 | 2004 | 14.795 | 2003 | 14.85 | 2002 | 14.906 | 2001 | 14.962 | 2000 | 15.13 | 1999 | 15.414 | 1998 | 15.702 | 1997 | 15.994 | 1996 | 16.29 | 1995 | 16.482 | 1994 | 16.566 | 1993 | 16.651 | 1992 | 16.736 | 1991 | 16.821 | 1990 | 16.928 | 1989 | 17.064 | 1988 | 17.201 | 1987 | 17.34 | 1986 | 17.479 | 1985 | 17.619 | 1984 | 17.759 | 1983 | 17.901 | 1982 | 18.043 | 1981 | 18.187 | 1980 | 18.274 | 1979 | 18.284 | 1978 | 18.294 | 1977 | 18.304 | 1976 | 18.314 | 1975 | 18.324 | 1974 | 18.334 | 1973 | 18.344 | 1972 | 18.354 | 1971 | 18.364 | 1970 | 18.453 | 1969 | 18.654 | 1968 | 18.855 | 1967 | 19.059 | 1966 | 19.264 | 1965 | 19.471 | 1964 | 19.679 | 1963 | 19.89 | 1962 | 20.102 | 1961 | 20.315 | 1960 | 20.437 |
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