Year | Value | 2022 | 49.303302554666 | 2021 | 49.334118996528 | 2020 | 49.360418680598 | 2019 | 49.373544032142 | 2018 | 49.376125284999 | 2017 | 49.376930530488 | 2016 | 49.380565702042 | 2015 | 49.389873388064 | 2014 | 49.403586665883 | 2013 | 49.41913705912 | 2012 | 49.434742599981 | 2011 | 49.44988400623 | 2010 | 49.46420827083 | 2009 | 49.478735991675 | 2008 | 49.495533673353 | 2007 | 49.51421241233 | 2006 | 49.53277670376 | 2005 | 49.549792117371 | 2004 | 49.566258073445 | 2003 | 49.583842850183 | 2002 | 49.603298062864 | 2001 | 49.625247330587 | 2000 | 49.648904689478 | 1999 | 49.67383078304 | 1998 | 49.699929481056 | 1997 | 49.726718471597 | 1996 | 49.753993529202 | 1995 | 49.78190636718 | 1994 | 49.810911947006 | 1993 | 49.841632472414 | 1992 | 49.874376230865 | 1991 | 49.908146720481 | 1990 | 49.941341463538 | 1989 | 49.972767383586 | 1988 | 50.001326114535 | 1987 | 50.025327542538 | 1986 | 50.043596314979 | 1985 | 50.055046228193 | 1984 | 50.062469866533 | 1983 | 50.068530327848 | 1982 | 50.07198635412 | 1981 | 50.073687796848 | 1980 | 50.074137971542 | 1979 | 50.072877221966 | 1978 | 50.069789927918 | 1977 | 50.064932286246 | 1976 | 50.058043737043 | 1975 | 50.049395970241 | 1974 | 50.039381390523 | 1973 | 50.028531475576 | 1972 | 50.016729796322 | 1971 | 50.003333269019 | 1970 | 49.988524415919 | 1969 | 49.972533701996 | 1968 | 49.955151598166 | 1967 | 49.936323796352 | 1966 | 49.916383181758 | 1965 | 49.895993688708 | 1964 | 49.875516875826 | 1963 | 49.854941236268 | 1962 | 49.834728093384 | 1961 | 49.815200624579 | 1960 | 49.796235111254 |
|