Year | Value | 2021 | 50,465.972 | 2020 | 50,470 | 2019 | 50,370 | 2018 | 50,300 | 2017 | 50,295.2 | 2016 | 50,210 | 2015 | 50,119 | 2014 | 49,770 | 2013 | 49,950 | 2012 | 51,230 | 2011 | 50,880 | 2010 | 50,520 | 2009 | 50,300 | 2008 | 51,010 | 2007 | 51,160 | 2006 | 51,900 | 2005 | 52,650 | 2004 | 53,300 | 2003 | 53,260 | 2002 | 53,250 | 2001 | 54,980 | 2000 | 55,820 | 1999 | 56,790 | 1998 | 56,450 | 1997 | 62,030 | 1996 | 61,640 | 1995 | 61,640 | 1994 | 61,590 | 1993 | 61,210 | 1992 | 61,540 | 1991 | 61,610 | 1990 | 61,590 | 1989 | 61,680 | 1988 | 61,620 | 1987 | 61,660 | 1986 | 61,660 | 1985 | 61,690 | 1984 | 61,720 | 1983 | 61,770 | 1982 | 61,820 | 1981 | 61,790 | 1980 | 61,810 | 1979 | 62,060 | 1978 | 62,110 | 1977 | 62,060 | 1976 | 61,980 | 1975 | 59,550 | 1974 | 60,380 |
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