| Year | Value | | 2022 | 27,637 | | 2021 | 27,020 | | 2020 | 26,373 | | 2019 | 25,792 | | 2018 | 25,302 | | 2017 | 24,877 | | 2016 | 24,495 | | 2015 | 24,122 | | 2014 | 23,731 | | 2013 | 23,318 | | 2012 | 22,886 | | 2011 | 22,427 | | 2010 | 21,947 | | 2009 | 21,464 | | 2008 | 20,976 | | 2007 | 20,475 | | 2006 | 19,954 | | 2005 | 19,422 | | 2004 | 18,905 | | 2003 | 18,417 | | 2002 | 17,955 | | 2001 | 17,532 | | 2000 | 17,142 | | 1999 | 16,723 | | 1998 | 16,221 | | 1997 | 15,653 | | 1996 | 15,040 | | 1995 | 14,385 | | 1994 | 13,750 | | 1993 | 13,175 | | 1992 | 12,625 | | 1991 | 12,086 | | 1990 | 11,559 | | 1989 | 11,039 | | 1988 | 10,543 | | 1987 | 10,065 | | 1986 | 9,571 | | 1985 | 9,090 | | 1984 | 8,667 | | 1983 | 8,296 | | 1982 | 7,983 | | 1981 | 7,753 | | 1980 | 7,573 | | 1979 | 7,404 | | 1978 | 7,232 | | 1977 | 7,044 | | 1976 | 6,841 | | 1975 | 6,639 | | 1974 | 6,440 | | 1973 | 6,238 | | 1972 | 6,052 | | 1971 | 5,889 | | 1970 | 5,767 | | 1969 | 5,679 | | 1968 | 5,593 | | 1967 | 5,510 | | 1966 | 5,428 | | 1965 | 5,339 | | 1964 | 5,237 | | 1963 | 5,127 | | 1962 | 5,012 | | 1961 | 4,895 | | 1960 | 4,779 |
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