Year | Value | 2022 | 49.731442502373 | 2021 | 49.742003670833 | 2020 | 49.802775824609 | 2019 | 49.923304499359 | 2018 | 50.041122091775 | 2017 | 50.15802576449 | 2016 | 50.275069138094 | 2015 | 50.393779116539 | 2014 | 50.468091012797 | 2013 | 50.492140897348 | 2012 | 50.516006444523 | 2011 | 50.541890810394 | 2010 | 50.599454524332 | 2009 | 50.694033666768 | 2008 | 50.78590170366 | 2007 | 50.86967416936 | 2006 | 50.951643101556 | 2005 | 51.037022553121 | 2004 | 51.119284507307 | 2003 | 51.194650074821 | 2002 | 51.265042719231 | 2001 | 51.314283523675 | 2000 | 51.349895355582 | 1999 | 51.390577572635 | 1998 | 51.435387086018 | 1997 | 51.481183298255 | 1996 | 51.525795122941 | 1995 | 51.572291982446 | 1994 | 51.620453247861 | 1993 | 51.667959541795 | 1992 | 51.715327367501 | 1991 | 51.758847761857 | 1990 | 51.772284725663 | 1989 | 51.76145602925 | 1988 | 51.751614142227 | 1987 | 51.742007988833 | 1986 | 51.734581919318 | 1985 | 51.728332338037 | 1984 | 51.72000384548 | 1983 | 51.709189493887 | 1982 | 51.701491112868 | 1981 | 51.701125073057 | 1980 | 51.709902869734 | 1979 | 51.726604389803 | 1978 | 51.74471813167 | 1977 | 51.763242899119 | 1976 | 51.780514555699 | 1975 | 51.7957187608 | 1974 | 51.812741327748 | 1973 | 51.829688408501 | 1972 | 51.843890718757 | 1971 | 51.860268588013 | 1970 | 51.89698877726 | 1969 | 51.953023058535 | 1968 | 52.014922500289 | 1967 | 52.079337812239 | 1966 | 52.144339138204 | 1965 | 52.209915463328 | 1964 | 52.27662018226 | 1963 | 52.349891326933 | 1962 | 52.427638467627 | 1961 | 52.500582539675 | 1960 | 52.554091065667 |
|