Year Years 1970 3.689 1971 3.696 1972 2.95 1973 1.467 1974 1.233 1975 1.911 1976 2.386 1977 0.9745 1978 -0.1532 1979 -1.066 1980 -3.067 1981 -0.648 1982 0.09334 1983 -0.00248 1984 -0.1365 1985 -1.894 1986 -1.243 1987 -1.293 1988 -0.7564 1989 -0.2555 1990 2.419 1991 0.1277 1992 -3.238 1993 -1.546 1994 -0.4931 1995 0.04115 1996 0.4994 1997 0.802 1998 -2.023 1999 -1.613 2000 1.736 2001 -1.096 2002 1.896 2003 0.7457