Year | Value | 2021 | 39,500 | 2020 | 39,500 | 2019 | 39,500 | 2018 | 39,500 | 2017 | 39,500 | 2016 | 39,500 | 2015 | 39,500 | 2014 | 39,500 | 2013 | 39,500 | 2012 | 37,500 | 2011 | 36,500 | 2010 | 36,500 | 2009 | 36,500 | 2008 | 35,500 | 2007 | 33,500 | 2006 | 33,400 | 2005 | 34,840 | 2004 | 34,670 | 2003 | 34,670 | 2002 | 33,650 | 2001 | 32,650 | 2000 | 31,950 | 1999 | 31,100 | 1998 | 30,500 | 1997 | 28,900 | 1996 | 27,100 | 1995 | 25,200 | 1994 | 24,000 | 1993 | 23,200 | 1992 | 22,950 | 1991 | 22,800 | 1990 | 22,700 | 1989 | 22,200 | 1988 | 22,100 | 1987 | 22,000 | 1986 | 21,900 | 1985 | 21,300 | 1984 | 21,100 | 1983 | 21,000 | 1982 | 20,900 | 1981 | 20,570 | 1980 | 20,270 | 1979 | 19,970 | 1978 | 19,770 | 1977 | 19,570 | 1976 | 19,270 | 1975 | 18,970 | 1974 | 18,570 | 1973 | 18,270 | 1972 | 18,070 | 1971 | 17,770 | 1970 | 17,270 | 1969 | 17,070 | 1968 | 16,220 | 1967 | 15,920 | 1966 | 15,520 | 1965 | 15,220 | 1964 | 15,020 | 1963 | 14,820 | 1962 | 14,620 | 1961 | 14,420 |
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