Year | Value | 2021 | 60.241743463186 | 2020 | 60.848894424466 | 2019 | 61.244290518923 | 2018 | 60.863027538892 | 2017 | 60.47713845715 | 2016 | 60.06902467312 | 2015 | 59.562981700059 | 2014 | 59.142658201913 | 2013 | 58.668043004746 | 2012 | 58.141013248679 | 2011 | 57.558610685099 | 2010 | 56.84736568908 | 2009 | 56.219613071159 | 2008 | 55.450712605246 | 2007 | 54.849028544875 | 2006 | 54.213301069583 | 2005 | 53.462195048548 | 2004 | 52.848807119108 | 2003 | 52.36952152081 | 2002 | 51.891342436414 | 2001 | 51.536321825006 | 2000 | 51.264544802803 | 1999 | 50.640838184178 | 1998 | 49.927786874302 | 1997 | 50.215336709664 | 1996 | 50.048528333099 | 1995 | 50.114174071595 | 1994 | 50.002159883343 | 1993 | 49.696932518781 | 1992 | 49.472160671428 | 1991 | 49.699631027607 | 1990 | 49.824307633488 | 1989 | 49.884869493393 | 1988 | 49.020197675458 | 1987 | 49.338121581985 | 1986 | 49.007069873759 | 1985 | 48.6127475268 | 1984 | 48.361807745154 | 1983 | 48.332148192393 | 1982 | 49.176041684887 | 1981 | 48.93781946045 | 1980 | 48.572455755033 | 1979 | 48.2100289146 | 1978 | 47.748586960162 | 1977 | 47.447803211481 | 1976 | 46.984952204866 | 1975 | 46.306432704088 | 1974 | 45.920461663804 | 1973 | 45.708795356985 | 1972 | 44.987343657165 | 1971 | 44.870803968841 | 1970 | 44.369830237344 | 1969 | 43.911307167478 | 1968 | 43.670734775988 | 1967 | 43.232178331786 | 1966 | 42.984090052141 | 1965 | 43.029451291312 | 1964 | 42.890837726942 | 1963 | 42.440620261289 | 1962 | 42.200720575525 | 1961 | 41.739739358076 | 1960 | 41.422545776448 |
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