| Year | Value | | 2022 | 20,605 | | 2021 | 21,145 | | 2020 | 21,744 | | 2019 | 22,142 | | 2018 | 22,669 | | 2017 | 23,369 | | 2016 | 24,330 | | 2015 | 25,547 | | 2014 | 26,908 | | 2013 | 28,344 | | 2012 | 29,847 | | 2011 | 29,187 | | 2010 | 26,458 | | 2009 | 24,050 | | 2008 | 22,043 | | 2007 | 20,519 | | 2006 | 19,545 | | 2005 | 19,029 | | 2004 | 18,770 | | 2003 | 18,671 | | 2002 | 17,245 | | 2001 | 13,853 | | 2000 | 10,278 | | 1999 | 7,492 | | 1998 | 5,501 | | 1997 | 4,669 | | 1996 | 4,228 | | 1995 | 3,715 | | 1994 | 5,529 | | 1993 | 7,482 | | 1992 | 7,565 | | 1991 | 7,650 | | 1990 | 7,756 | | 1989 | 7,899 | | 1988 | 7,987 | | 1987 | 7,937 | | 1986 | 7,778 | | 1985 | 7,627 | | 1984 | 7,569 | | 1983 | 7,574 | | 1982 | 7,515 | | 1981 | 7,361 | | 1980 | 7,208 | | 1979 | 7,080 | | 1978 | 6,977 | | 1977 | 6,890 | | 1976 | 6,788 | | 1975 | 6,686 | | 1974 | 6,604 | | 1973 | 6,540 | | 1972 | 6,485 | | 1971 | 6,404 | | 1970 | 6,265 | | 1969 | 6,062 | | 1968 | 5,787 | | 1967 | 5,443 | | 1966 | 5,073 | | 1965 | 4,714 | | 1964 | 4,368 | | 1963 | 4,035 | | 1962 | 3,705 | | 1961 | 3,385 | | 1960 | 3,104 |
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