Year | Value | 2022 | 49.669625802387 | 2021 | 49.670666222445 | 2020 | 49.682344039251 | 2019 | 49.702487043791 | 2018 | 49.724055909316 | 2017 | 49.756575317425 | 2016 | 49.789406377978 | 2015 | 49.851073395527 | 2014 | 49.919164707977 | 2013 | 49.972747327213 | 2012 | 50.054939359386 | 2011 | 50.163255539303 | 2010 | 50.257163705208 | 2009 | 50.322977174673 | 2008 | 50.397126689656 | 2007 | 50.440537814566 | 2006 | 50.461681103462 | 2005 | 50.490900486168 | 2004 | 50.539551058569 | 2003 | 50.626895697583 | 2002 | 50.686120386712 | 2001 | 50.701869688385 | 2000 | 50.671903550736 | 1999 | 50.658089339908 | 1998 | 50.726201324916 | 1997 | 50.791207688134 | 1996 | 50.821148009932 | 1995 | 50.826842641088 | 1994 | 50.8107341752 | 1993 | 50.808299533397 | 1992 | 50.8349594908 | 1991 | 50.894800452382 | 1990 | 51.004676512785 | 1989 | 51.12601439452 | 1988 | 51.222980355192 | 1987 | 51.291137464038 | 1986 | 51.334437895537 | 1985 | 51.350739222738 | 1984 | 51.361614526804 | 1983 | 51.356994308231 | 1982 | 51.295271491973 | 1981 | 51.219980629566 | 1980 | 51.158379176392 | 1979 | 51.090562419406 | 1978 | 51.028750737394 | 1977 | 50.974831619993 | 1976 | 50.918685320423 | 1975 | 50.873140194421 | 1974 | 50.834549940664 | 1973 | 50.781531905632 | 1972 | 50.805451934385 | 1971 | 50.930926891462 | 1970 | 50.965987116243 | 1969 | 50.918324814724 | 1968 | 50.890086219685 | 1967 | 50.860948861604 | 1966 | 50.822201542941 | 1965 | 50.774726041104 | 1964 | 50.736449903941 | 1963 | 50.712989851582 | 1962 | 50.681565223916 | 1961 | 50.643267095617 | 1960 | 50.604771969138 |
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