Year | Value | 2022 | 15.271 | 2021 | 15.492 | 2020 | 15.713 | 2019 | 15.935 | 2018 | 16.156 | 2017 | 16.378 | 2016 | 16.599 | 2015 | 16.82 | 2014 | 17.04 | 2013 | 17.26 | 2012 | 17.48 | 2011 | 17.698 | 2010 | 17.916 | 2009 | 18.133 | 2008 | 18.351 | 2007 | 18.573 | 2006 | 18.796 | 2005 | 19.021 | 2004 | 19.246 | 2003 | 19.47 | 2002 | 19.696 | 2001 | 19.923 | 2000 | 20.152 | 1999 | 20.384 | 1998 | 20.617 | 1997 | 20.853 | 1996 | 21.09 | 1995 | 21.33 | 1994 | 21.571 | 1993 | 21.814 | 1992 | 22.149 | 1991 | 22.777 | 1990 | 23.417 | 1989 | 24.07 | 1988 | 24.733 | 1987 | 25.411 | 1986 | 26.1 | 1985 | 27.353 | 1984 | 28.64 | 1983 | 29.967 | 1982 | 31.327 | 1981 | 32.719 | 1980 | 34.14 | 1979 | 35.595 | 1978 | 37.075 | 1977 | 38.579 | 1976 | 40.103 | 1975 | 41.651 | 1974 | 43.296 | 1973 | 45.288 | 1972 | 47.293 | 1971 | 49.312 | 1970 | 51.331 | 1969 | 53.345 | 1968 | 55.346 | 1967 | 57.335 | 1966 | 59.298 | 1965 | 61.231 | 1964 | 63.128 | 1963 | 64.989 | 1962 | 66.482 | 1961 | 67.627 | 1960 | 68.75 |
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