1971  436.0
 1972  490.0
 1973  448.5
 1974  591.0
 1975  378.0
 1976  557.5
 1977  478.0
 1978  599.0
 1979  436.5
 1980  547.0
 1981  530.5
 1982  349.0
 1983  739.5
 1984  453.0
 1985  468.5
 1986  619.5
 1987  373.5
 1988  553.0
 1989  465.5
 1990  564.5
 1991  546.0
 1992  536.0
 1993  500.0
 1994  515.0
 1995  511.0
 1996  611.5
 1997  515.0
 1998  589.0
 1999  439.0
 2000  576.0