| Year | Value | | 2021 | 303,947.7 | | 2020 | 303,940 | | 2019 | 303,930 | | 2018 | 303,920 | | 2017 | 303,920 | | 2016 | 303,910 | | 2015 | 303,910 | | 2014 | 303,890 | | 2013 | 303,890 | | 2012 | 303,890 | | 2011 | 303,890 | | 2010 | 303,900 | | 2009 | 303,900 | | 2008 | 303,900 | | 2007 | 304,090 | | 2006 | 304,110 | | 2005 | 304,590 | | 2004 | 304,590 | | 2003 | 304,590 | | 2002 | 304,590 | | 2001 | 304,590 | | 2000 | 304,590 | | 1999 | 304,590 | | 1998 | 304,590 | | 1997 | 304,590 | | 1996 | 304,590 | | 1995 | 304,590 | | 1994 | 304,590 | | 1993 | 304,590 | | 1992 | 304,590 | | 1991 | 304,590 | | 1990 | 304,590 | | 1989 | 304,590 | | 1988 | 304,590 | | 1987 | 304,590 | | 1986 | 304,590 | | 1985 | 304,590 | | 1984 | 304,590 | | 1983 | 304,590 | | 1982 | 304,590 | | 1981 | 304,590 | | 1980 | 304,590 | | 1979 | 304,590 | | 1978 | 304,590 | | 1977 | 304,590 | | 1976 | 304,590 | | 1975 | 304,590 | | 1974 | 304,590 |
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