Year | Value | 2022 | 49.084933824155 | 2021 | 49.086402968319 | 2020 | 49.093083297575 | 2019 | 49.088613634832 | 2018 | 49.075557201909 | 2017 | 49.059345339919 | 2016 | 49.041230923849 | 2015 | 49.019846376693 | 2014 | 48.996985327904 | 2013 | 48.974299591148 | 2012 | 48.950346418845 | 2011 | 48.925627539459 | 2010 | 48.911642491089 | 2009 | 48.90787699181 | 2008 | 48.902731614828 | 2007 | 48.895314981107 | 2006 | 48.888722062247 | 2005 | 48.88344951797 | 2004 | 48.879053426457 | 2003 | 48.876209348841 | 2002 | 48.876637112723 | 2001 | 48.878297512118 | 2000 | 48.875923015328 | 1999 | 48.868169332713 | 1998 | 48.85994557574 | 1997 | 48.853314503443 | 1996 | 48.846759834992 | 1995 | 48.839203787479 | 1994 | 48.830384123913 | 1993 | 48.820687588667 | 1992 | 48.809887663171 | 1991 | 48.795915183448 | 1990 | 48.780173199588 | 1989 | 48.764455605409 | 1988 | 48.74983291335 | 1987 | 48.737445844748 | 1986 | 48.725445947308 | 1985 | 48.714557949961 | 1984 | 48.706993981492 | 1983 | 48.700582674482 | 1982 | 48.694710143664 | 1981 | 48.690075660518 | 1980 | 48.683412344579 | 1979 | 48.678900345213 | 1978 | 48.680915641755 | 1977 | 48.685071418783 | 1976 | 48.68665813949 | 1975 | 48.685823242869 | 1974 | 48.680061770919 | 1973 | 48.670010503613 | 1972 | 48.657236258024 | 1971 | 48.63751859749 | 1970 | 48.615340063426 | 1969 | 48.602269215089 | 1968 | 48.597474396018 | 1967 | 48.60282083272 | 1966 | 48.616019361903 | 1965 | 48.624796928543 | 1964 | 48.620954759164 | 1963 | 48.609317845793 | 1962 | 48.597396796517 | 1961 | 48.586168526758 | 1960 | 48.573910195719 |
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