| Year | Value | | 2022 | 34,255 | | 2021 | 34,114 | | 2020 | 33,812 | | 2019 | 32,977 | | 2018 | 31,871 | | 2017 | 30,747 | | 2016 | 29,645 | | 2015 | 28,576 | | 2014 | 27,525 | | 2013 | 26,456 | | 2012 | 25,376 | | 2011 | 24,349 | | 2010 | 23,393 | | 2009 | 22,498 | | 2008 | 21,676 | | 2007 | 20,910 | | 2006 | 20,135 | | 2005 | 19,334 | | 2004 | 18,515 | | 2003 | 17,677 | | 2002 | 16,851 | | 2001 | 16,130 | | 2000 | 15,580 | | 1999 | 15,199 | | 1998 | 15,051 | | 1997 | 15,049 | | 1996 | 15,034 | | 1995 | 14,992 | | 1994 | 14,923 | | 1993 | 14,826 | | 1992 | 14,718 | | 1991 | 14,665 | | 1990 | 14,717 | | 1989 | 14,874 | | 1988 | 15,131 | | 1987 | 14,943 | | 1986 | 14,260 | | 1985 | 13,592 | | 1984 | 12,941 | | 1983 | 12,308 | | 1982 | 11,678 | | 1981 | 11,028 | | 1980 | 10,346 | | 1979 | 9,623 | | 1978 | 8,848 | | 1977 | 8,014 | | 1976 | 7,146 | | 1975 | 6,268 | | 1974 | 5,754 | | 1973 | 5,620 | | 1972 | 5,501 | | 1971 | 5,374 | | 1970 | 5,224 | | 1969 | 5,043 | | 1968 | 4,830 | | 1967 | 4,598 | | 1966 | 4,384 | | 1965 | 4,232 | | 1964 | 4,147 | | 1963 | 4,135 | | 1962 | 4,198 | | 1961 | 4,304 | | 1960 | 4,428 |
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