Year | Value | 2022 | 46.613381591515 | 2021 | 46.764444355636 | 2020 | 46.91463730312 | 2019 | 47.057306647095 | 2018 | 47.185912297144 | 2017 | 47.314213900698 | 2016 | 47.433441494976 | 2015 | 47.541414161065 | 2014 | 47.629687666251 | 2013 | 47.693593957216 | 2012 | 47.741307397898 | 2011 | 47.779673871824 | 2010 | 47.801058958753 | 2009 | 47.834540280087 | 2008 | 47.870062545782 | 2007 | 47.87760428892 | 2006 | 47.870702442871 | 2005 | 47.852668551197 | 2004 | 47.82515012694 | 2003 | 47.789128327492 | 2002 | 47.75493153864 | 2001 | 47.725126381868 | 2000 | 47.75985580256 | 1999 | 47.856288313688 | 1998 | 47.954485907849 | 1997 | 48.054071938366 | 1996 | 48.149210081142 | 1995 | 48.2436638506 | 1994 | 48.333511949416 | 1993 | 48.410087719298 | 1992 | 48.485743832176 | 1991 | 48.572815149354 | 1990 | 48.586184635249 | 1989 | 48.507618244082 | 1988 | 48.417596328823 | 1987 | 48.322061762303 | 1986 | 48.229914831822 | 1985 | 48.153308736949 | 1984 | 48.090098082705 | 1983 | 48.037158230807 | 1982 | 47.991911306062 | 1981 | 47.958757424784 | 1980 | 47.926324503311 | 1979 | 47.997071214067 | 1978 | 48.193577407923 | 1977 | 48.396335780692 | 1976 | 48.598781754651 | 1975 | 48.81280110117 | 1974 | 49.028080523144 | 1973 | 49.248644877368 | 1972 | 49.495020735182 | 1971 | 49.772771296172 | 1970 | 49.922768968887 | 1969 | 49.972505040742 | 1968 | 50.095386137215 | 1967 | 50.234211862972 | 1966 | 50.380281690141 | 1965 | 50.536914201759 | 1964 | 50.672728959822 | 1963 | 50.783636770075 | 1962 | 50.909429842081 | 1961 | 51.048631350363 | 1960 | 50.378868567603 |
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