| YEAR | ISMR (mm) | Normalised Percentage of Departure | DRY or WET |
| 1960 | 839.8 | −0.14 | |
| 1961 | 1020.3 | 1.99 | WET |
| 1962 | 809.8 | −0.5 | |
| 1963 | 857.9 | 0.07 | |
| 1964 | 922.6 | 0.83 | |
| 1965 | 709.4 | −1.69 | DRY |
| 1966 | 739.9 | −1.33 | |
| 1967 | 860.1 | 0.09 | |
| 1968 | 754.6 | −1.16 | |
| 1969 | 831 | −0.25 | |
| 1970 | 938.8 | 1.03 | |
| 1971 | 886.8 | 0.41 | |
| 1972 | 652.9 | −2.36 | DRY |
| 1973 | 913.4 | 0.72 | |
| 1974 | 748.1 | −1.23 | |
| 1975 | 962.9 | 1.31 | WET |
| 1976 | 856.8 | 0.05 | |
| 1977 | 883.2 | 0.36 | |
| 1978 | 909.3 | 0.67 | |
| 1979 | 707.8 | −1.71 | DRY |
| 1980 | 882.8 | 0.36 | |
| 1981 | 852.2 | 0 | |
| 1982 | 735.4 | −1.38 | DRY |
| 1983 | 955.7 | 1.22 | WET |
| 1984 | 836.7 | −0.19 | |
| 1985 | 759.8 | −1.1 | |
| 1986 | 743 | −1.29 | |
| 1987 | 697.3 | −1.84 | DRY |
| 1988 | 961.5 | 1.29 | WET |
| 1989 | 866.7 | 0.17 | |
| 1990 | 908.7 | 0.67 | |
| 1991 | 784.6 | −0.78 | |
| 1992 | 784.9 | −0.78 | |
| 1993 | 896.7 | 0.29 | |
| 1994 | 953 | 1.19 | WET |
| 1995 | 827 | −0.3 | |
| 1996 | 853 | 0 | |
| 1997 | 872 | 0.23 | |
| 1998 | 874 | 0.26 |