| Year | Value | | 2019 | 316 | | 2018 | 316 | | 2017 | 316 | | 2016 | 12,137 | | 2015 | 60,382 | | 2014 | 64,188 | | 2013 | 64,524 | | 2012 | 65,404.363636364 | | 2011 | 63,186 | | 2010 | 59,658 | | 2009 | 63,876 | | 2008 | 84,660 | | 2007 | 101,753 | | 2006 | 95,721 | | 2005 | 87,523 | | 2004 | 83,916 | | 2003 | 94,563 | | 2002 | 104,255 | | 2001 | 77,798 | | 2000 | 82,764 | | 1999 | 75,200 | | 1998 | 43,800 | | 1997 | 44,000 | | 1996 | 44,000 | | 1995 | 44,000 | | 1994 | 44,000 | | 1993 | 44,000 | | 1992 | 44,000 | | 1991 | 42,500 | | 1990 | 42,500 | | 1989 | 42,500 | | 1988 | 40,000 | | 1987 | 40,000 | | 1986 | 37,500 | | 1985 | 73,800 | | 1984 | 73,200 | | 1983 | 44,000 | | 1982 | 44,000 | | 1981 | 44,000 | | 1980 | 44,000 |
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