f0¡(WATERYEARN TWOROCKN TWOROCK3WN PETALUM3WNN  1953 28.23 1954 27.49 1955 21.74 1956 45.67 1957 20.90 1958 53.17 47.58 1959 25.87 36.75 31.82 1960 34.12 21.40 20.34 1961 23.15 20.84 20.76 1962 32.30 23.70 22.23 1963 44.35 36.36 30.58 1964 25.25 20.23 17.68 1965 40.35 34.55 30.97 1966 40.56 30.83 1967 33.84 36.99 1968 26.21 27.05 1969 36.79 43.34 1970 31.68 34.07 1971 26.93 32.08 1972 15.34 1973 35.92 39.95 1974 27.00 33.69 1975 17.19 23.72 1976 9.15 13.14 1977 8.75 1978 33.53 43.06 1979 21.93 25.30 1980 34.46 38.88 1981 16.75 20.73 1982 42.53 47.79 1983 53.91 1984 1985 32.31 1986 1987 14.73 1988 1989 19.88 1990 21.36 1991 19.53 1992 26.33 1993 49.99 1994 23.29 1995 37.68 1996 1997 21.23 1998 51.72 1999 37.76 2000 21.69