Year | Value | 2023 | 22.537 | 2022 | 22.978 | 2021 | 23.431 | 2020 | 23.895 | 2019 | 24.37 | 2018 | 24.857 | 2017 | 25.356 | 2016 | 25.866 | 2015 | 26.389 | 2014 | 26.923 | 2013 | 27.469 | 2012 | 28.026 | 2011 | 28.598 | 2010 | 29.175 | 2009 | 29.759 | 2008 | 30.349 | 2007 | 30.947 | 2006 | 31.55 | 2005 | 32.16 | 2004 | 32.775 | 2003 | 33.398 | 2002 | 34.026 | 2001 | 34.66 | 2000 | 35.259 | 1999 | 35.777 | 1998 | 36.297 | 1997 | 36.821 | 1996 | 37.347 | 1995 | 37.877 | 1994 | 38.41 | 1993 | 38.945 | 1992 | 39.482 | 1991 | 40.024 | 1990 | 40.797 | 1989 | 42.101 | 1988 | 43.413 | 1987 | 44.739 | 1986 | 46.07 | 1985 | 47.552 | 1984 | 49.366 | 1983 | 51.188 | 1982 | 53.003 | 1981 | 54.811 | 1980 | 56.22 | 1979 | 56.645 | 1978 | 57.069 | 1977 | 57.492 | 1976 | 57.913 | 1975 | 58.414 | 1974 | 59.08 |
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