# year value 1900 5.231295 1901 5.193352 1902 5.160767 1903 4.807962 1904 4.923296 1905 5.066845 1906 5.11446 1907 5.093494 1908 5.130058 1909 5.158002 1910 5.17861 1911 5.171866 1912 5.11875 1913 5.022134 1914 5.125149 1915 5.229655 1916 5.242927 1917 5.264113 1918 5.312311 1919 5.269506 1920 5.297352 1921 5.296387 1922 5.323453 1923 5.315168 1924 5.315019 1925 5.329442 1926 5.325881 1927 5.372297 1928 5.392338 1929 5.322389 1930 5.286175 1931 5.304961 1932 5.344253 1933 5.292761 1934 5.264843 1935 5.34456 1936 5.419547 1937 5.404156 1938 5.42232 1939 5.392317 1940 5.398364 1941 5.397474 1942 5.400074 1943 5.401879 1944 5.42665 1945 5.403608 1946 5.377221 1947 5.405062 1948 5.42534 1949 5.480948 1950 5.422984 1951 5.435534 1952 5.41242 1953 5.372183 1954 5.377902 1955 5.401808 1956 5.423806 1957 5.408255 1958 5.403013 1959 5.405962 1960 5.451177 1961 5.394261 1962 5.356861 1963 5.263273 1964 5.119362 1965 5.184577 1966 5.246114 1967 5.28669 1968 5.24157 1969 5.225525 1970 5.302854 1971 5.388351 1972 5.418405 1973 5.417949 1974 5.411959 1975 5.378688 1976 5.447737 1977 5.45762 1978 5.520577 1979 5.552952 1980 5.638092 1981 5.650061 1982 5.492137 1983 5.302865 1984 5.50049 1985 5.56962 1986 5.589065 1987 5.648322 1988 5.724006 1989 5.779665 1990 5.807721 1991 5.768171 1992 5.35747 1993 5.563303 1994 5.673347 1995 5.730391 1996 5.842858 1997 5.931332 1998 5.991684 1999 6.000216 2000 6.048938 2001 6.130764 2002 6.1488 2003 6.133692 2004 6.1479 2005 6.197764