| Year | Value | | 2022 | 15,748 | | 2021 | 15,541 | | 2020 | 15,558 | | 2019 | 15,276 | | 2018 | 14,810 | | 2017 | 14,289 | | 2016 | 13,832 | | 2015 | 13,604 | | 2014 | 13,570 | | 2013 | 13,717 | | 2012 | 14,090 | | 2011 | 14,549 | | 2010 | 14,842 | | 2009 | 14,829 | | 2008 | 14,625 | | 2007 | 13,896 | | 2006 | 12,504 | | 2005 | 11,041 | | 2004 | 9,756 | | 2003 | 8,646 | | 2002 | 8,063 | | 2001 | 8,125 | | 2000 | 8,355 | | 1999 | 8,455 | | 1998 | 8,341 | | 1997 | 8,137 | | 1996 | 7,949 | | 1995 | 7,706 | | 1994 | 7,470 | | 1993 | 7,311 | | 1992 | 7,157 | | 1991 | 7,019 | | 1990 | 6,835 | | 1989 | 6,842 | | 1988 | 6,899 | | 1987 | 6,971 | | 1986 | 7,014 | | 1985 | 6,947 | | 1984 | 6,800 | | 1983 | 6,681 | | 1982 | 6,417 | | 1981 | 6,084 | | 1980 | 5,837 | | 1979 | 5,624 | | 1978 | 5,500 | | 1977 | 5,467 | | 1976 | 5,547 | | 1975 | 5,681 | | 1974 | 5,835 | | 1973 | 6,044 | | 1972 | 6,246 | | 1971 | 6,414 | | 1970 | 6,520 | | 1969 | 6,578 | | 1968 | 6,586 | | 1967 | 6,516 | | 1966 | 6,375 | | 1965 | 6,192 | | 1964 | 5,982 | | 1963 | 5,771 | | 1962 | 5,605 | | 1961 | 5,482 | | 1960 | 5,414 |
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