Year | Value | 2022 | 47.760843829656 | 2021 | 47.748849483474 | 2020 | 47.738064404731 | 2019 | 47.723004440006 | 2018 | 47.710256913976 | 2017 | 47.696967701577 | 2016 | 47.674572677885 | 2015 | 47.645678833902 | 2014 | 47.613070957909 | 2013 | 47.567714159802 | 2012 | 47.508953623651 | 2011 | 47.436266992586 | 2010 | 47.373825777467 | 2009 | 47.332434286796 | 2008 | 47.287119674238 | 2007 | 47.240782286383 | 2006 | 47.198219914704 | 2005 | 47.152211746735 | 2004 | 47.108600093741 | 2003 | 47.0637207813 | 2002 | 47.02506639031 | 2001 | 47.013055172866 | 2000 | 47.041502897875 | 1999 | 47.116674117121 | 1998 | 47.23447059472 | 1997 | 47.368642758853 | 1996 | 47.524284363449 | 1995 | 47.689990935408 | 1994 | 47.857526240458 | 1993 | 48.032931312088 | 1992 | 48.209839310846 | 1991 | 48.272935851903 | 1990 | 48.152475997979 | 1989 | 47.952416870953 | 1988 | 47.744678190741 | 1987 | 47.545568971144 | 1986 | 47.349796019285 | 1985 | 47.146722420367 | 1984 | 46.937058229552 | 1983 | 46.839836105675 | 1982 | 46.859621958885 | 1981 | 46.882107074805 | 1980 | 46.900090924502 | 1979 | 46.919159869368 | 1978 | 46.936840305306 | 1977 | 46.956345431009 | 1976 | 46.987029223316 | 1975 | 47.032091824783 | 1974 | 47.094272633841 | 1973 | 47.161937855824 | 1972 | 47.224669603524 | 1971 | 47.275702882552 | 1970 | 47.297611482245 | 1969 | 47.336136299457 | 1968 | 47.414536052858 | 1967 | 47.493386565396 | 1966 | 47.575682586818 | 1965 | 47.656092817383 | 1964 | 47.724328378563 | 1963 | 47.746547128665 | 1962 | 47.730143137805 | 1961 | 47.705573828785 | 1960 | 47.661812005349 |
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