Year | Value | 2022 | 43.588410812717 | 2021 | 43.031379651582 | 2020 | 42.479173857595 | 2019 | 41.931031935813 | 2018 | 41.382683111321 | 2017 | 40.828644504997 | 2016 | 40.273537436435 | 2015 | 39.721718226437 | 2014 | 39.173233732158 | 2013 | 38.625152906524 | 2012 | 38.070215277295 | 2011 | 37.521775106667 | 2010 | 36.970568206227 | 2009 | 36.427479606439 | 2008 | 35.892234086341 | 2007 | 35.375714685781 | 2006 | 34.979092998558 | 2005 | 34.516043747633 | 2004 | 34.011294702933 | 2003 | 33.528462719201 | 2002 | 33.066461235229 | 2001 | 32.618968209455 | 2000 | 32.1573899882 | 1999 | 31.776753685622 | 1998 | 31.407199531564 | 1997 | 31.034055682871 | 1996 | 30.659942607299 | 1995 | 30.307178678367 | 1994 | 29.977600713059 | 1993 | 29.611268663234 | 1992 | 29.182469977748 | 1991 | 28.774507926393 | 1990 | 28.372159204986 | 1989 | 27.856363191943 | 1988 | 27.310261875864 | 1987 | 26.730506539697 | 1986 | 26.120957782763 | 1985 | 25.517261778441 | 1984 | 24.922430839546 | 1983 | 24.346221899475 | 1982 | 23.811682121461 | 1981 | 23.285623676765 | 1980 | 22.756487608469 | 1979 | 22.295790915156 | 1978 | 21.82662477144 | 1977 | 21.299097454391 | 1976 | 20.771198192977 | 1975 | 20.22951245823 | 1974 | 19.69791580431 | 1973 | 19.173904053829 | 1972 | 18.635745725998 | 1971 | 18.103156505788 | 1970 | 17.595486698462 | 1969 | 17.14146495239 | 1968 | 16.683445803065 | 1967 | 16.239580627247 | 1966 | 15.820662859042 | 1965 | 15.409339978351 | 1964 | 14.982231505954 | 1963 | 14.568963615407 | 1962 | 14.173193118888 | 1961 | 13.799640066373 | 1960 | 13.442564947539 |
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