# year value 1940 -0.5059314 1941 -0.4817494 1942 -0.4584737 1943 -0.4467191 1944 -0.3766453 1945 -0.4418239 1946 -0.4676667 1947 -0.3845741 1948 -0.4138356 1949 -0.4296009 1950 -0.3850484 1951 -0.4755584 1952 -0.5100901 1953 -0.4257704 1954 -0.4454394 1955 -0.3839137 1956 -0.464027 1957 -0.4395151 1958 -0.4953249 1959 -0.4460025 1960 -0.483448 1961 -0.4880347 1962 -0.3974769 1963 -0.554678 1964 -0.7234868 1965 -0.6837905 1966 -0.6092668 1967 -0.6577709 1968 -0.7120692 1969 -0.696294 1970 -0.5459455 1971 -0.4710377 1972 -0.4757952 1973 -0.4034647 1974 -0.3989744 1975 -0.4870557 1976 -0.4569271 1977 -0.345171 1978 -0.3450227 1979 -0.3081727 1980 -0.2745996 1981 -0.1897837 1982 -0.3272454 1983 -0.5767645 1984 -0.3485853 1985 -0.3159489 1986 -0.2711295 1987 -0.2384191 1988 -0.1182802 1989 -0.07648808 1990 -0.06182167 1991 -0.08351602 1992 -0.5550354 1993 -0.3764961 1994 -0.2177848 1995 -0.09165553 1996 0.03533799 1997 0.03868813 1998 0.08795038 1999 0.1125999 2000 0.221012 2001 0.2599106 2002 0.3064068 2003 0.3104898 2004 0.3485934 2005 1.349782