1971    -999    -999    -999   -16.0   -20.0   -20.0   -22.0   -22.0   -24.0   -16.0   -12.0    -5.0
1972    -2.0    -6.0   -13.0   -14.0   -22.0   -21.0   -21.0   -24.0   -21.0   -21.0   -12.0    -4.0
1973    -4.0   -10.0   -14.0   -18.0   -19.0   -21.0   -22.0   -24.0   -25.0   -21.0    -9.0    -5.0
1974    -4.0    -8.0   -12.0   -19.0   -21.0   -18.0   -26.0   -23.0   -21.0   -20.0   -10.0    -4.0
1975    -3.0    -7.0   -13.0   -18.0   -23.0   -25.0   -23.0   -27.0   -25.0   -21.0   -11.0    -4.0
1976    -3.0    -7.0   -13.0   -22.0   -22.0   -26.0   -25.0   -25.0   -26.0   -24.0   -10.0    -3.0
1977    -2.0    -8.0   -12.0   -17.0   -24.0   -22.0   -27.0   -23.0   -24.0   -18.0   -10.0    -4.0
1978    -5.0    -6.0   -10.0   -15.0   -23.0   -25.0   -20.0   -26.0   -23.0   -17.0    -8.0    -3.0
1979    -3.0    -999   -11.0   -15.0   -21.0   -22.0   -27.0   -23.0   -20.0   -17.0    -8.0    -2.0
1980    -3.0    -6.0    -8.0   -14.0   -18.0   -24.0   -25.0   -23.0   -20.0   -20.0    -8.0    -4.0
1981    -4.0    -5.0    -9.0   -15.0   -20.0   -20.0   -22.0   -21.0   -20.0   -11.0   -10.0    -4.0
1982    -3.0    -6.0   -12.0   -19.0   -19.0   -19.0   -24.0   -26.0   -22.0   -17.0    -9.0    -3.0
1983    -2.0    -4.0   -11.0   -17.0   -18.0   -23.0   -27.0   -28.0   -20.0   -20.0   -12.0    -4.0
1984    -4.0    -8.0   -13.0   -19.0   -20.0   -27.0   -29.0   -23.0   -21.0   -16.0   -11.0    -5.0
1985    -4.0    -7.0   -12.0   -17.0   -21.0   -23.0   -25.0   -25.0   -24.0   -20.0   -11.0    -5.0
1986    -4.0    -7.0    -9.0   -16.0   -20.0   -19.0   -23.0   -24.0   -24.0   -18.0   -10.0    -5.0
1987    -3.0    -6.0    -9.0   -16.0   -22.0   -20.0   -21.0   -24.0   -22.0   -16.0   -11.0    -5.0
1988    -4.0    -6.0   -11.0   -16.0   -22.0   -23.0   -25.0   -25.0   -19.0   -16.0    -9.0    -3.0
1989    -3.0    -7.0   -11.0   -17.0   -23.0   -28.0   -23.0   -26.0   -20.0   -18.0   -10.0    -4.0
1990    -3.0    -7.0   -12.0   -20.0   -18.0   -25.0   -19.0   -26.0   -25.0   -18.0   -10.0    -4.0
1991    -3.0    -6.0    -999    -999    -999    -999    -999    -999    -999    -999    -999    -999