| Year | Value | | 2022 | 6,953 | | 2021 | 6,815 | | 2020 | 6,664 | | 2019 | 6,470 | | 2018 | 6,250 | | 2017 | 6,050 | | 2016 | 5,875 | | 2015 | 5,727 | | 2014 | 5,604 | | 2013 | 5,505 | | 2012 | 5,433 | | 2011 | 5,385 | | 2010 | 5,364 | | 2009 | 5,364 | | 2008 | 5,383 | | 2007 | 5,418 | | 2006 | 5,465 | | 2005 | 5,527 | | 2004 | 5,593 | | 2003 | 5,663 | | 2002 | 5,738 | | 2001 | 5,817 | | 2000 | 5,904 | | 1999 | 6,011 | | 1998 | 6,142 | | 1997 | 6,284 | | 1996 | 6,426 | | 1995 | 6,574 | | 1994 | 6,718 | | 1993 | 6,851 | | 1992 | 6,998 | | 1991 | 7,197 | | 1990 | 7,296 | | 1989 | 7,247 | | 1988 | 7,173 | | 1987 | 7,074 | | 1986 | 6,957 | | 1985 | 6,828 | | 1984 | 6,698 | | 1983 | 6,579 | | 1982 | 6,479 | | 1981 | 6,396 | | 1980 | 6,323 | | 1979 | 6,373 | | 1978 | 6,179 | | 1977 | 5,548 | | 1976 | 4,818 | | 1975 | 4,072 | | 1974 | 3,379 | | 1973 | 3,071 | | 1972 | 3,123 | | 1971 | 3,188 | | 1970 | 3,203 | | 1969 | 3,174 | | 1968 | 3,098 | | 1967 | 2,961 | | 1966 | 2,850 | | 1965 | 2,812 | | 1964 | 2,826 | | 1963 | 2,854 | | 1962 | 2,878 | | 1961 | 2,902 | | 1960 | 2,908 |
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