| Year | Value | | 2022 | 18,569 | | 2021 | 18,354 | | 2020 | 18,120 | | 2019 | 17,798 | | 2018 | 17,397 | | 2017 | 16,969 | | 2016 | 16,507 | | 2015 | 16,035 | | 2014 | 15,573 | | 2013 | 15,116 | | 2012 | 14,665 | | 2011 | 14,211 | | 2010 | 13,739 | | 2009 | 13,261 | | 2008 | 12,795 | | 2007 | 12,351 | | 2006 | 11,962 | | 2005 | 11,633 | | 2004 | 11,333 | | 2003 | 11,020 | | 2002 | 10,690 | | 2001 | 10,364 | | 2000 | 10,006 | | 1999 | 9,593 | | 1998 | 9,163 | | 1997 | 8,726 | | 1996 | 8,302 | | 1995 | 7,971 | | 1994 | 7,770 | | 1993 | 7,633 | | 1992 | 7,496 | | 1991 | 7,360 | | 1990 | 7,241 | | 1989 | 7,098 | | 1988 | 6,907 | | 1987 | 6,667 | | 1986 | 6,365 | | 1985 | 6,029 | | 1984 | 5,699 | | 1983 | 5,382 | | 1982 | 5,066 | | 1981 | 4,769 | | 1980 | 4,526 | | 1979 | 4,323 | | 1978 | 4,124 | | 1977 | 3,919 | | 1976 | 3,713 | | 1975 | 3,521 | | 1974 | 3,373 | | 1973 | 3,278 | | 1972 | 3,213 | | 1971 | 3,173 | | 1970 | 3,155 | | 1969 | 3,153 | | 1968 | 3,158 | | 1967 | 3,166 | | 1966 | 3,173 | | 1965 | 3,175 | | 1964 | 3,176 | | 1963 | 3,176 | | 1962 | 3,179 | | 1961 | 3,176 | | 1960 | 3,162 |
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