Year | Value | 2021 | 78.730050944773 | 2020 | 79.974125834538 | 2019 | 81.016079634442 | 2018 | 80.780991856419 | 2017 | 80.712564946477 | 2016 | 80.822087465819 | 2015 | 80.371809508526 | 2014 | 80.518572688555 | 2013 | 80.205375242818 | 2012 | 79.930324767821 | 2011 | 79.901671698058 | 2010 | 79.282092515253 | 2009 | 78.952364260788 | 2008 | 78.62221176941 | 2007 | 78.316209504134 | 2006 | 78.194521137228 | 2005 | 77.954511345491 | 2004 | 77.807557925556 | 2003 | 77.459427012555 | 2002 | 77.334690128364 | 2001 | 77.132998762503 | 2000 | 76.781985849926 | 1999 | 76.350292010245 | 1998 | 76.093178110827 | 1997 | 75.744678593193 | 1996 | 75.580010931301 | 1995 | 75.385993995062 | 1994 | 75.218158026532 | 1993 | 75.134132512083 | 1992 | 75.021414200144 | 1991 | 74.789480633937 | 1990 | 74.8200850125 | 1989 | 74.742001411065 | 1988 | 74.755704017694 | 1987 | 74.48485512364 | 1986 | 74.403483348346 | 1985 | 74.193057369889 | 1984 | 74.223124614356 | 1983 | 74.229593650713 | 1982 | 74.20021946775 | 1981 | 74.114888463486 | 1980 | 73.637956512397 | 1979 | 73.882481980856 | 1978 | 73.705633244079 | 1977 | 73.763582722691 | 1976 | 73.734604696817 | 1975 | 73.523584458345 | 1974 | 73.571911177075 | 1973 | 73.365545302726 | 1972 | 73.18131212441 | 1971 | 72.796016040083 | 1970 | 72.494653225132 | 1969 | 72.186862457078 | 1968 | 72.576821532485 | 1967 | 72.224481169414 | 1966 | 72.599683029436 | 1965 | 72.009062216066 | 1964 | 71.835828469547 | 1963 | 71.347238957409 | 1962 | 70.307913552197 | 1961 | 70.819918678436 | 1960 | 70.452923331555 |
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