Year | Value | 2022 | 48.016083275842 | 2021 | 48.217589167798 | 2020 | 48.395627085491 | 2019 | 48.587352819775 | 2018 | 48.716889227692 | 2017 | 48.803109165246 | 2016 | 48.930803037106 | 2015 | 49.043746408453 | 2014 | 49.143248467075 | 2013 | 49.227808625392 | 2012 | 49.296720015923 | 2011 | 49.367135396886 | 2010 | 49.407700238049 | 2009 | 49.426636505204 | 2008 | 49.439281812308 | 2007 | 49.448862235637 | 2006 | 49.456490384608 | 2005 | 49.462471096251 | 2004 | 49.465279078873 | 2003 | 49.47791550508 | 2002 | 49.494694649094 | 2001 | 49.528361410774 | 2000 | 49.602704165256 | 1999 | 49.74036585448 | 1998 | 49.887512030395 | 1997 | 50.038267290823 | 1996 | 50.189625133518 | 1995 | 50.343836121653 | 1994 | 50.495524704619 | 1993 | 50.63822447084 | 1992 | 50.780367979199 | 1991 | 50.927816090684 | 1990 | 51.109304491736 | 1989 | 51.326946739269 | 1988 | 51.555369440291 | 1987 | 51.781004172953 | 1986 | 52.00356839169 | 1985 | 52.226529800101 | 1984 | 52.441889099709 | 1983 | 52.646474310518 | 1982 | 52.842843224995 | 1981 | 53.158887085286 | 1980 | 53.468143315883 | 1979 | 54.079720558142 | 1978 | 54.712898847286 | 1977 | 55.350426127009 | 1976 | 55.992258109446 | 1975 | 56.641276213767 | 1974 | 57.294556051284 | 1973 | 57.952227493596 | 1972 | 58.613340569409 | 1971 | 59.182784292447 | 1970 | 59.658038457687 | 1969 | 60.187674109743 | 1968 | 60.736585327708 | 1967 | 61.286593008975 | 1966 | 61.831150040949 | 1965 | 62.370589586499 | 1964 | 62.903811603878 | 1963 | 63.450660609865 | 1962 | 63.999940476867 | 1961 | 64.542762864008 | 1960 | 65.076529975831 |
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