| Year | Value | | 2022 | 32,589 | | 2021 | 31,603 | | 2020 | 30,490 | | 2019 | 29,210 | | 2018 | 28,088 | | 2017 | 27,584 | | 2016 | 27,476 | | 2015 | 27,076 | | 2014 | 26,631 | | 2013 | 26,106 | | 2012 | 25,178 | | 2011 | 24,181 | | 2010 | 23,059 | | 2009 | 21,970 | | 2008 | 20,957 | | 2007 | 19,879 | | 2006 | 18,828 | | 2005 | 17,837 | | 2004 | 16,883 | | 2003 | 15,960 | | 2002 | 15,084 | | 2001 | 14,250 | | 2000 | 13,445 | | 1999 | 12,698 | | 1998 | 12,463 | | 1997 | 12,351 | | 1996 | 11,926 | | 1995 | 11,541 | | 1994 | 11,058 | | 1993 | 10,694 | | 1992 | 10,549 | | 1991 | 10,304 | | 1990 | 9,961 | | 1989 | 9,772 | | 1988 | 10,426 | | 1987 | 11,049 | | 1986 | 10,812 | | 1985 | 10,451 | | 1984 | 10,117 | | 1983 | 9,785 | | 1982 | 9,423 | | 1981 | 9,054 | | 1980 | 8,705 | | 1979 | 8,382 | | 1978 | 8,079 | | 1977 | 7,795 | | 1976 | 7,548 | | 1975 | 7,332 | | 1974 | 7,144 | | 1973 | 6,977 | | 1972 | 6,886 | | 1971 | 6,872 | | 1970 | 6,958 | | 1969 | 7,151 | | 1968 | 7,340 | | 1967 | 7,518 | | 1966 | 7,718 | | 1965 | 7,870 | | 1964 | 7,874 | | 1963 | 7,881 | | 1962 | 7,910 | | 1961 | 7,882 | | 1960 | 7,861 |
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