| Year | Value | | 2022 | 2,167 | | 2021 | 2,138 | | 2020 | 2,105 | | 2019 | 2,045 | | 2018 | 1,985 | | 2017 | 1,927 | | 2016 | 1,879 | | 2015 | 1,849 | | 2014 | 1,825 | | 2013 | 1,796 | | 2012 | 1,770 | | 2011 | 1,755 | | 2010 | 1,754 | | 2009 | 1,768 | | 2008 | 1,797 | | 2007 | 1,775 | | 2006 | 1,706 | | 2005 | 1,654 | | 2004 | 1,611 | | 2003 | 1,572 | | 2002 | 1,545 | | 2001 | 1,513 | | 2000 | 1,469 | | 1999 | 1,420 | | 1998 | 1,359 | | 1997 | 1,284 | | 1996 | 1,239 | | 1995 | 1,230 | | 1994 | 1,212 | | 1993 | 1,186 | | 1992 | 1,155 | | 1991 | 1,125 | | 1990 | 1,096 | | 1989 | 1,071 | | 1988 | 1,052 | | 1987 | 1,039 | | 1986 | 982 | | 1985 | 906 | | 1984 | 871 | | 1983 | 854 | | 1982 | 845 | | 1981 | 847 | | 1980 | 852 | | 1979 | 856 | | 1978 | 863 | | 1977 | 876 | | 1976 | 880 | | 1975 | 864 | | 1974 | 844 | | 1973 | 838 | | 1972 | 840 | | 1971 | 848 | | 1970 | 874 | | 1969 | 921 | | 1968 | 987 | | 1967 | 1,074 | | 1966 | 1,037 | | 1965 | 934 | | 1964 | 928 | | 1963 | 948 | | 1962 | 963 | | 1961 | 974 | | 1960 | 981 |
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