| Year | Value | | 2022 | 18,999 | | 2021 | 18,432 | | 2020 | 17,850 | | 2019 | 17,293 | | 2018 | 16,771 | | 2017 | 16,276 | | 2016 | 15,821 | | 2015 | 15,405 | | 2014 | 14,952 | | 2013 | 14,418 | | 2012 | 13,838 | | 2011 | 13,223 | | 2010 | 12,586 | | 2009 | 11,987 | | 2008 | 11,465 | | 2007 | 10,991 | | 2006 | 10,539 | | 2005 | 10,106 | | 2004 | 9,682 | | 2003 | 9,285 | | 2002 | 8,907 | | 2001 | 8,519 | | 2000 | 8,138 | | 1999 | 7,802 | | 1998 | 7,502 | | 1997 | 7,243 | | 1996 | 7,054 | | 1995 | 6,906 | | 1994 | 6,763 | | 1993 | 6,610 | | 1992 | 6,439 | | 1991 | 6,251 | | 1990 | 6,055 | | 1989 | 5,846 | | 1988 | 5,620 | | 1987 | 5,392 | | 1986 | 5,169 | | 1985 | 4,964 | | 1984 | 4,784 | | 1983 | 4,626 | | 1982 | 4,481 | | 1981 | 4,350 | | 1980 | 4,226 | | 1979 | 4,099 | | 1978 | 3,970 | | 1977 | 3,840 | | 1976 | 3,712 | | 1975 | 3,606 | | 1974 | 3,537 | | 1973 | 3,494 | | 1972 | 3,468 | | 1971 | 3,452 | | 1970 | 3,408 | | 1969 | 3,332 | | 1968 | 3,248 | | 1967 | 3,163 | | 1966 | 3,077 | | 1965 | 2,988 | | 1964 | 2,893 | | 1963 | 2,794 | | 1962 | 2,694 | | 1961 | 2,592 | | 1960 | 2,490 |
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