Year Years 1964 4.346 1965 7.151 1966 4.296 1967 4.283 1968 2.291 1969 1.487 1970 0.1471 1971 -1.292 1972 -0.8992 1973 -1.919 1974 -2.864 1975 -4.58 1976 -3.69 1977 -4.403 1978 -2.129 1979 -1.407 1980 0.4151 1981 0.5397 1982 0.9234 1983 1.861 1984 3.144 1985 4.449 1986 4.125 1987 4.537 1988 2.166 1989 -0.3959 1990 -2.22 1991 -2.172 1992 -2.728 1993 -2.886 1994 -3.166 1995 -2.863 1996 -3.479 1997 -2.992 1998 -2.341 1999 -0.4288 2000 0.983 2001 1.371 2002 1.489 2003 0.9289