1964 -999 -999 -999 -999 -999 -23.8 -23.6 -24.7 -28.7 -24.4 -20.5 -17.0 1965 -16.4 -17.6 -18.8 -19.7 -21.0 -22.3 -27.1 -26.6 -27.4 -25.0 -22.3 -16.2 1966 -17.9 -17.2 -19.8 -21.1 -21.1 -25.1 -24.4 -26.7 -24.4 -24.8 -20.0 -17.4 1967 -16.1 -18.6 -19.3 -21.3 -20.9 -22.3 -24.1 -24.7 -24.4 -21.2 -20.6 -18.0 1968 -17.4 -16.4 -19.1 -21.4 -20.6 -23.1 -26.9 -25.7 -30.0 -24.5 -22.3 -18.5 1969 -16.3 -16.6 -19.5 -20.5 -23.6 -21.5 -26.2 -29.2 -27.4 -23.2 -19.8 -17.7 1970 -18.2 -18.7 -17.6 -21.2 -23.3 -23.9 -24.8 -27.8 -27.5 -23.7 -18.9 -18.2 1971 -15.9 -17.0 -19.2 -22.3 -23.0 -25.1 -26.6 -26.9 -24.3 -25.1 -21.7 -16.2 1972 -16.0 -18.6 -20.0 -19.3 -22.2 -22.7 -27.4 -23.7 -24.3 -23.7 -21.8 -16.2 1973 -16.9 -18.1 -19.1 -20.5 -19.9 -21.5 -25.4 -27.4 -23.7 -24.3 -22.1 -19.5 1974 -15.5 -18.2 -19.7 -22.1 -22.1 -23.3 -24.5 -24.9 -25.3 -23.7 -20.9 -17.9 1975 -16.8 -18.0 -18.6 -22.9 -21.4 -24.4 -25.3 -25.9 -25.9 -25.8 -21.8 -18.6 1976 -16.3 -18.8 -19.8 -21.7 -24.7 -23.5 -28.4 -25.7 -27.0 -25.3 -20.8 -15.4 1977 -16.4 -18.1 -19.3 -21.1 -20.9 -23.0 -22.3 -22.8 -25.7 -23.3 -21.8 -19.2 1978 -20.0 -17.7 -20.9 -21.4 -23.5 -25.1 -24.1 -29.1 -24.7 -22.9 -20.8 -19.4 1979 -17.2 -18.7 -19.1 -19.6 -22.6 -26.7 -26.3 -27.7 -25.7 -22.8 -18.8 -16.4 1980 -16.8 -17.7 -18.0 -19.9 -20.9 -23.5 -22.4 -24.8 -23.5 -24.0 -19.6 -18.1 1981 -17.4 -15.3 -19.5 -22.1 -21.5 -23.7 -20.3 -23.0 -24.1 -26.4 -20.7 -16.9 1982 -16.6 -17.5 -19.1 -20.6 -21.9 -23.1 -26.0 -24.9 -25.7 -24.2 -18.5 -14.9 1983 -17.6 -17.9 -19.8 -19.7 -21.0 -22.7 -24.7 -27.0 -21.8 -22.2 -20.9 -18.9 1984 -16.4 -16.3 -17.4 -20.5 -19.3 -23.8 -25.4 -24.1 -24.2 -24.8 -19.6 -15.5 1985 -16.5 -17.3 -18.6 -18.9 -24.3 -21.8 -23.0 -26.5 -23.9 -24.0 -20.0 -18.6 1986 -16.3 -16.9 -18.5 -20.9 -22.1 -23.6 -25.7 -23.0 -24.2 -22.5 -20.1 -18.8 1987 -16.5 -16.6 -18.0 -19.8 -21.4 -22.1 -24.1 -25.7 -26.5 -23.2 -19.6 -18.6 1988 -15.2 -18.9 -14.9 -22.0 -21.5 -21.7 -25.1 -26.8 -23.7 -22.3 -22.6 -18.1 1989 -16.8 -17.4 -19.2 -22.3 -24.5 -23.2 -25.3 -26.1 -25.7 -23.8 -20.4 -18.3 1990 -16.8 -18.3 -19.3 -22.0 -20.9 -24.8 -20.4 -27.1 -29.9 -22.3 -20.6 -19.0 1991 -17.8 -16.0 -18.8 -22.3 -22.8 -22.3 -23.8 -24.4 -25.9 -24.1 -21.8 -14.2 1992 -15.8 -18.7 -17.8 -19.7 -21.0 -22.3 -24.1 -25.9 -27.9 -24.3 -22.4 -18.5 1993 -16.5 -18.1 -19.8 -22.3 -22.9 -24.0 -25.4 -25.6 -25.0 -22.4 -21.7 -19.1 1994 -19.1 -19.0 -19.5 -21.1 -999 -999 -999 -999 -999 -999 -999 -999 1995 -999 -999 -999 -999 -23.4 -24.9 -23.4 -25.1 -27.3 -22.6 -21.4 -17.8 1996 -16.9 -15.5 -19.9 -21.6 -999 -999 -21.2 -999 -999 -999 -999 -999 1997 -17.5 -17.0 -19.3 -19.4 -21.1 -999 -999 -24.1 -26.1 -23.7 -18.1 -18.5 1998 -17.4 -999 -999 -999 -999 -999 -999 -999 -999 -999 -999 -999