Year | Value | 2021 | 59.87258063232 | 2020 | 60.249531838873 | 2019 | 60.721657370973 | 2018 | 60.35483877541 | 2017 | 59.950611346928 | 2016 | 59.523915062775 | 2015 | 59.119371262141 | 2014 | 58.752196541558 | 2013 | 58.330059291371 | 2012 | 57.869792700539 | 2011 | 57.387106517469 | 2010 | 56.811968283324 | 2009 | 56.308003512547 | 2008 | 55.613654377499 | 2007 | 55.086780138025 | 2006 | 54.57857535332 | 2005 | 53.939779172236 | 2004 | 53.339801647141 | 2003 | 52.883792790201 | 2002 | 52.368116135501 | 2001 | 51.921561427143 | 2000 | 51.473936000652 | 1999 | 50.728399945111 | 1998 | 49.633202148607 | 1997 | 49.97010470767 | 1996 | 49.729267629115 | 1995 | 49.716325461574 | 1994 | 49.901049423887 | 1993 | 49.057588197397 | 1992 | 48.563163021371 | 1991 | 48.649862011621 | 1990 | 48.728726211776 | 1989 | 48.688479610376 | 1988 | 47.538169886864 | 1987 | 47.978546330555 | 1986 | 48.418443198984 | 1985 | 47.89467833009 | 1984 | 47.74843907666 | 1983 | 47.978321337427 | 1982 | 48.200145353828 | 1981 | 48.037607414841 | 1980 | 47.77564171165 | 1979 | 47.630776726598 | 1978 | 47.288353382363 | 1977 | 47.008695715994 | 1976 | 46.457697992903 | 1975 | 45.86477198576 | 1974 | 45.419197581624 | 1973 | 44.985131460123 | 1972 | 44.116946447327 | 1971 | 43.815081568227 | 1970 | 43.199400197147 | 1969 | 42.639337279677 | 1968 | 42.34081340453 | 1967 | 41.814107627673 | 1966 | 41.775967920777 | 1965 | 41.54163267399 | 1964 | 41.380300572618 | 1963 | 40.938064338547 | 1962 | 40.653190928159 | 1961 | 40.141829084227 | 1960 | 39.856067355355 |
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