| Year | Value | | 2022 | 20,906 | | 2021 | 20,084 | | 2020 | 19,364 | | 2019 | 18,703 | | 2018 | 18,068 | | 2017 | 17,441 | | 2016 | 16,828 | | 2015 | 16,248 | | 2014 | 15,722 | | 2013 | 15,280 | | 2012 | 14,935 | | 2011 | 14,670 | | 2010 | 14,454 | | 2009 | 14,253 | | 2008 | 14,034 | | 2007 | 13,773 | | 2006 | 13,449 | | 2005 | 13,060 | | 2004 | 12,603 | | 2003 | 12,103 | | 2002 | 11,674 | | 2001 | 11,390 | | 2000 | 11,248 | | 1999 | 11,203 | | 1998 | 11,019 | | 1997 | 10,654 | | 1996 | 10,254 | | 1995 | 9,836 | | 1994 | 9,344 | | 1993 | 8,788 | | 1992 | 8,302 | | 1991 | 7,943 | | 1990 | 7,674 | | 1989 | 7,528 | | 1988 | 7,510 | | 1987 | 7,482 | | 1986 | 7,403 | | 1985 | 7,292 | | 1984 | 7,161 | | 1983 | 7,019 | | 1982 | 6,871 | | 1981 | 6,701 | | 1980 | 6,517 | | 1979 | 6,350 | | 1978 | 6,201 | | 1977 | 6,057 | | 1976 | 5,910 | | 1975 | 5,769 | | 1974 | 5,636 | | 1973 | 5,507 | | 1972 | 5,386 | | 1971 | 5,274 | | 1970 | 5,179 | | 1969 | 5,096 | | 1968 | 5,028 | | 1967 | 4,970 | | 1966 | 4,943 | | 1965 | 4,947 | | 1964 | 4,959 | | 1963 | 4,976 | | 1962 | 4,994 | | 1961 | 5,007 | | 1960 | 5,015 |
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