Year | Value | 2022 | 60.867845581734 | 2021 | 61.09469566335 | 2020 | 62.085346235274 | 2019 | 63.542220681121 | 2018 | 64.578691837727 | 2017 | 65.191791722059 | 2016 | 65.1725870666 | 2015 | 64.755392463719 | 2014 | 64.634607772443 | 2013 | 64.442447362629 | 2012 | 63.360484944616 | 2011 | 61.541752549994 | 2010 | 59.297501590957 | 2009 | 57.871347084396 | 2008 | 57.667855639397 | 2007 | 57.453429020992 | 2006 | 57.229358650873 | 2005 | 56.996006666688 | 2004 | 56.753312770495 | 2003 | 56.713439710479 | 2002 | 56.900542048602 | 2001 | 57.107375267039 | 2000 | 57.321756653399 | 1999 | 57.543976476693 | 1998 | 57.77432999653 | 1997 | 58.012823367421 | 1996 | 58.260202230088 | 1995 | 58.518681144692 | 1994 | 58.79058432048 | 1993 | 58.698189266884 | 1992 | 58.170325106398 | 1991 | 57.561232743787 | 1990 | 56.891512664836 | 1989 | 56.149589401099 | 1988 | 55.322886746789 | 1987 | 54.397329769896 | 1986 | 53.356966592446 | 1985 | 52.179615736181 | 1984 | 51.471366662845 | 1983 | 51.339253843102 | 1982 | 51.188393930955 | 1981 | 51.026938781582 | 1980 | 50.864209179311 | 1979 | 50.693880008429 | 1978 | 50.50835387565 | 1977 | 50.320046552226 | 1976 | 50.146526858403 | 1975 | 50.010289712574 | 1974 | 49.955875104018 | 1973 | 49.960952350888 | 1972 | 49.970411485146 | 1971 | 49.977424604713 | 1970 | 49.980244314463 | 1969 | 49.985847461647 | 1968 | 49.993645852781 | 1967 | 50.003215216979 | 1966 | 50.01580148073 | 1965 | 50.032502088217 | 1964 | 50.051995096621 | 1963 | 50.075887745932 | 1962 | 50.105090471139 | 1961 | 50.138989793995 | 1960 | 50.179385820226 |
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