Year Years 1960 1.94 1961 1.039 1962 1.005 1963 0.7956 1964 1.285 1965 1.547 1966 1.383 1967 1.721 1968 2.199 1969 2.055 1970 1.838 1971 1.892 1972 1.968 1973 1.934 1974 1.578 1975 0.9576 1976 0.9599 1977 0.8445 1978 0.3321 1979 0.272 1980 0.5426 1981 0.5168 1982 0.1396 1983 0.3616 1984 -0.7023 1985 -0.5897 1986 -0.6748 1987 -2.933 1988 -0.3643 1989 -1.387 1990 -0.8547 1991 -1.627 1992 0.9109 1993 1.314 1994 2.485 1995 2.794 1996 3.366 1997 6.272 1998 3.746 1999 5.357 2000 4.574 2001 5.163 2002 2.937 2003 1.483