Year Years 1969 -1.17 1970 -1.143 1971 0.1156 1972 0.4178 1973 0.4004 1974 0.515 1975 0.7517 1976 0.9351 1977 0.7217 1978 0.1103 1979 0.3632 1980 0.7987 1981 1.723 1982 1.21 1983 1.04 1984 0.5616 1985 1.253 1986 1.589 1987 1.75 1988 2.344 1989 2.029 1990 1.032 1991 0.8827 1992 0.6275 1993 0.8075 1994 1.43 1995 0.4905 1996 0.09892 1997 -0.2482 1998 -0.568 1999 0.3791 2000 1.186 2001 0.8691 2002 1.431 2003 2.585 2004 2.325