| Year | Value | | 2022 | 17,307 | | 2021 | 17,223 | | 2020 | 17,069 | | 2019 | 16,951 | | 2018 | 16,586 | | 2017 | 16,045 | | 2016 | 15,637 | | 2015 | 15,143 | | 2014 | 14,593 | | 2013 | 14,028 | | 2012 | 13,475 | | 2011 | 13,001 | | 2010 | 12,630 | | 2009 | 12,323 | | 2008 | 12,054 | | 2007 | 11,778 | | 2006 | 11,446 | | 2005 | 11,036 | | 2004 | 10,548 | | 2003 | 10,021 | | 2002 | 9,532 | | 2001 | 9,134 | | 2000 | 8,850 | | 1999 | 8,680 | | 1998 | 8,602 | | 1997 | 8,580 | | 1996 | 8,573 | | 1995 | 8,548 | | 1994 | 8,490 | | 1993 | 8,413 | | 1992 | 8,343 | | 1991 | 8,311 | | 1990 | 8,364 | | 1989 | 8,488 | | 1988 | 8,646 | | 1987 | 8,834 | | 1986 | 9,041 | | 1985 | 9,249 | | 1984 | 9,431 | | 1983 | 9,566 | | 1982 | 9,640 | | 1981 | 9,636 | | 1980 | 9,554 | | 1979 | 9,393 | | 1978 | 9,168 | | 1977 | 8,927 | | 1976 | 8,724 | | 1975 | 8,616 | | 1974 | 8,635 | | 1973 | 8,765 | | 1972 | 8,948 | | 1971 | 9,118 | | 1970 | 9,210 | | 1969 | 9,170 | | 1968 | 9,000 | | 1967 | 8,748 | | 1966 | 8,469 | | 1965 | 8,224 | | 1964 | 8,057 | | 1963 | 7,973 | | 1962 | 7,940 | | 1961 | 7,922 | | 1960 | 7,844 |
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