| Year | Value | | 2022 | 17,676 | | 2021 | 18,138 | | 2020 | 18,709 | | 2019 | 18,870 | | 2018 | 18,593 | | 2017 | 18,202 | | 2016 | 17,669 | | 2015 | 17,121 | | 2014 | 16,609 | | 2013 | 16,104 | | 2012 | 15,592 | | 2011 | 15,110 | | 2010 | 14,599 | | 2009 | 14,086 | | 2008 | 13,537 | | 2007 | 12,984 | | 2006 | 12,541 | | 2005 | 12,119 | | 2004 | 11,660 | | 2003 | 11,083 | | 2002 | 10,519 | | 2001 | 10,026 | | 2000 | 9,608 | | 1999 | 9,406 | | 1998 | 9,256 | | 1997 | 9,018 | | 1996 | 8,754 | | 1995 | 8,260 | | 1994 | 7,741 | | 1993 | 7,380 | | 1992 | 7,026 | | 1991 | 7,296 | | 1990 | 7,551 | | 1989 | 7,271 | | 1988 | 7,007 | | 1987 | 6,752 | | 1986 | 6,511 | | 1985 | 6,283 | | 1984 | 6,066 | | 1983 | 5,856 | | 1982 | 5,659 | | 1981 | 5,470 | | 1980 | 5,288 | | 1979 | 5,115 | | 1978 | 4,950 | | 1977 | 4,795 | | 1976 | 4,659 | | 1975 | 4,541 | | 1974 | 4,435 | | 1973 | 4,342 | | 1972 | 4,260 | | 1971 | 4,183 | | 1970 | 4,106 | | 1969 | 4,028 | | 1968 | 3,952 | | 1967 | 3,874 | | 1966 | 3,804 | | 1965 | 3,749 | | 1964 | 3,709 | | 1963 | 3,688 | | 1962 | 3,685 | | 1961 | 3,681 | | 1960 | 3,668 |
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