| Year | Value | | 2022 | 6,886 | | 2021 | 6,585 | | 2020 | 6,297 | | 2019 | 6,126 | | 2018 | 6,032 | | 2017 | 5,980 | | 2016 | 5,970 | | 2015 | 6,006 | | 2014 | 6,078 | | 2013 | 6,171 | | 2012 | 6,284 | | 2011 | 6,415 | | 2010 | 6,550 | | 2009 | 6,673 | | 2008 | 6,768 | | 2007 | 6,822 | | 2006 | 6,842 | | 2005 | 6,832 | | 2004 | 6,792 | | 2003 | 6,731 | | 2002 | 6,653 | | 2001 | 6,568 | | 2000 | 6,473 | | 1999 | 6,363 | | 1998 | 6,246 | | 1997 | 6,126 | | 1996 | 6,007 | | 1995 | 5,888 | | 1994 | 5,764 | | 1993 | 5,634 | | 1992 | 5,499 | | 1991 | 5,356 | | 1990 | 5,208 | | 1989 | 5,055 | | 1988 | 4,885 | | 1987 | 4,699 | | 1986 | 4,499 | | 1985 | 4,282 | | 1984 | 4,061 | | 1983 | 3,863 | | 1982 | 3,699 | | 1981 | 3,588 | | 1980 | 3,524 | | 1979 | 3,482 | | 1978 | 3,465 | | 1977 | 3,473 | | 1976 | 3,451 | | 1975 | 3,366 | | 1974 | 3,271 | | 1973 | 3,270 | | 1972 | 3,336 | | 1971 | 3,341 | | 1970 | 3,279 | | 1969 | 3,182 | | 1968 | 3,092 | | 1967 | 3,040 | | 1966 | 3,054 | | 1965 | 3,115 | | 1964 | 3,179 | | 1963 | 3,229 | | 1962 | 3,248 | | 1961 | 3,235 | | 1960 | 3,204 |
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