1981  372.5
 1982  317.5
 1983  268.5
 1984  281.0
 1985  319.5
 1986  306.0
 1987  305.0
 1988  291.0
 1989  231.5
 1990  333.0
 1991  446.0
 1992  239.0
 1993  296.0
 1994  422.0
 1995  279.5
 1996  415.0
 1997  266.5
 1998  253.5
 1999  353.0
 2000  331.0
 2001  236.5
 2002  377.5
 2003  241.0
 2004  381.0
 2005  446.0
 2006  310.0
 2007  341.5
 2008  308.0
 2009  388.0
 2010  278.0