Year | Value | 2021 | 16.951 | 2020 | 17.158 | 2019 | 17.463 | 2018 | 17.821 | 2017 | 19.006 | 2016 | 19.289 | 2015 | 19.181 | 2014 | 19.539 | 2013 | 19.649 | 2012 | 20.233 | 2011 | 21.727 | 2010 | 21.565 | 2009 | 22.772 | 2008 | 23.276 | 2007 | 23.738 | 2006 | 24.394 | 2005 | 25.004 | 2004 | 25.64 | 2003 | 26.413 | 2002 | 27.255 | 2001 | 28.101 | 2000 | 29.024 | 1999 | 29.812 | 1998 | 30.714 | 1997 | 31.739 | 1996 | 32.825 | 1995 | 34.008 | 1994 | 35.147 | 1993 | 36.24 | 1992 | 37.032 | 1991 | 37.744 | 1990 | 38.427 | 1989 | 39.094 | 1988 | 39.75 | 1987 | 40.175 | 1986 | 40.504 | 1985 | 40.745 | 1984 | 41.086 | 1983 | 41.395 | 1982 | 41.656 | 1981 | 42.001 | 1980 | 41.851 | 1979 | 41.836 | 1978 | 41.956 | 1977 | 42.128 | 1976 | 42.255 | 1975 | 42.338 | 1974 | 42.277 | 1973 | 42.188 | 1972 | 42.127 | 1971 | 41.983 | 1970 | 41.779 | 1969 | 42.027 | 1968 | 42.357 | 1967 | 42.806 | 1966 | 43.334 | 1965 | 43.932 | 1964 | 44.578 | 1963 | 45.239 | 1962 | 45.943 | 1961 | 46.323 | 1960 | 46.842 |
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