| Year | Value | | 2022 | 2,193 | | 2021 | 2,093 | | 2020 | 2,005 | | 2019 | 1,917 | | 2018 | 1,835 | | 2017 | 1,760 | | 2016 | 1,684 | | 2015 | 1,599 | | 2014 | 1,514 | | 2013 | 1,437 | | 2012 | 1,370 | | 2011 | 1,329 | | 2010 | 1,314 | | 2009 | 1,319 | | 2008 | 1,347 | | 2007 | 1,388 | | 2006 | 1,434 | | 2005 | 1,469 | | 2004 | 1,496 | | 2003 | 1,514 | | 2002 | 1,509 | | 2001 | 1,500 | | 2000 | 1,468 | | 1999 | 1,402 | | 1998 | 1,339 | | 1997 | 1,280 | | 1996 | 1,220 | | 1995 | 1,166 | | 1994 | 1,118 | | 1993 | 1,070 | | 1992 | 1,028 | | 1991 | 991 | | 1990 | 959 | | 1989 | 936 | | 1988 | 920 | | 1987 | 915 | | 1986 | 919 | | 1985 | 926 | | 1984 | 935 | | 1983 | 948 | | 1982 | 958 | | 1981 | 967 | | 1980 | 978 | | 1979 | 985 | | 1978 | 990 | | 1977 | 997 | | 1976 | 1,003 | | 1975 | 1,006 | | 1974 | 998 | | 1973 | 976 | | 1972 | 940 | | 1971 | 891 | | 1970 | 836 | | 1969 | 788 | | 1968 | 750 | | 1967 | 721 | | 1966 | 701 | | 1965 | 683 | | 1964 | 669 | | 1963 | 660 | | 1962 | 651 | | 1961 | 640 | | 1960 | 627 |
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