# year value 1940 -0.5297458 1941 -0.4856724 1942 -0.4652967 1943 -0.4631118 1944 -0.4761472 1945 -0.470863 1946 -0.5244583 1947 -0.5112163 1948 -0.4717155 1949 -0.3976343 1950 -0.490941 1951 -0.4587314 1952 -0.5485643 1953 -0.4863667 1954 -0.4616902 1955 -0.4992463 1956 -0.4191902 1957 -0.4650985 1958 -0.4526369 1959 -0.3994944 1960 -0.4175133 1961 -0.4294885 1962 -0.4854323 1963 -0.6133061 1964 -0.8211403 1965 -0.6931482 1966 -0.655457 1967 -0.6058999 1968 -0.5841906 1969 -0.6030869 1970 -0.5184062 1971 -0.4220599 1972 -0.4241797 1973 -0.3930725 1974 -0.4505182 1975 -0.4437496 1976 -0.3719921 1977 -0.3838487 1978 -0.3146023 1979 -0.2826958 1980 -0.1683774 1981 -0.1844039 1982 -0.3137357 1983 -0.4500432 1984 -0.2740428 1985 -0.3431604 1986 -0.2827081 1987 -0.1427394 1988 -0.09514981 1989 -0.08258097 1990 -0.01613048 1991 -0.1799139 1992 -0.4152131 1993 -0.2576775 1994 -0.2665598 1995 -0.162781 1996 0.02857564 1997 0.05836596 1998 0.0974033 1999 0.1566757 2000 0.1457426 2001 0.2698653 2002 0.2963512 2003 0.2106153 2004 0.2733837 2005 0.1314148