# year value 1940 -0.5118707 1941 -0.459116 1942 -0.4684859 1943 -0.4407836 1944 -0.3578785 1945 -0.4231857 1946 -0.4654091 1947 -0.3860184 1948 -0.4020218 1949 -0.4291022 1950 -0.3932858 1951 -0.4791276 1952 -0.5316546 1953 -0.4421366 1954 -0.4439325 1955 -0.3805797 1956 -0.456202 1957 -0.4352667 1958 -0.4831893 1959 -0.4282868 1960 -0.4626651 1961 -0.4784124 1962 -0.4028413 1963 -0.5520398 1964 -0.7259936 1965 -0.6611314 1966 -0.5953106 1967 -0.6683947 1968 -0.6986143 1969 -0.6900647 1970 -0.528024 1971 -0.4523162 1972 -0.457882 1973 -0.4338092 1974 -0.391206 1975 -0.474364 1976 -0.4512127 1977 -0.3511493 1978 -0.340416 1979 -0.3174979 1980 -0.2708663 1981 -0.167845 1982 -0.3088553 1983 -0.5555845 1984 -0.3343108 1985 -0.3231105 1986 -0.2692887 1987 -0.2175175 1988 -0.1280065 1989 -0.05774483 1990 -0.04145636 1991 -0.07534849 1992 -0.5548043 1993 -0.3627283 1994 -0.233469 1995 -0.1022918 1996 0.03438121 1997 0.0322498 1998 0.08769875 1999 0.1143368 2000 0.2173417 2001 0.2516907 2002 0.2823705 2003 0.3261298 2004 0.3332354 2005 1.351174