# year value 1901 -0.751651 1902 -0.1820498 1903 -2.032446 1904 -0.7927966 1905 -1.434666 1906 -0.3251123 1907 0.1647205 1908 0.493719 1909 -0.4397537 1910 -2.957314 1911 -0.4133813 1912 -1.710955 1913 -2.141327 1914 -0.2728647 1915 -1.663827 1916 -1.391285 1917 -2.853924 1918 -1.135363 1919 -0.7726418 1920 -0.8976598 1921 0.6679789 1922 -1.833186 1923 -0.5765485 1924 -0.4025785 1925 -1.179743 1926 0.8440307 1927 -0.07415362 1928 -1.046173 1929 -3.018769 1930 -0.5248955 1931 0.8901279 1932 -1.025667 1933 -2.384359 1934 2.01718 1935 0.5967401 1936 -1.801715 1937 -2.875563 1938 0.2663946 1939 -0.7033792 1940 0.303483 1941 1.019585 1942 -0.2931659 1943 0.1178592 1944 -0.1806744 1945 0.09137677 1946 -0.5479349 1947 0.07439446 1948 -0.9366491 1949 -3.570991 1950 -1.329634 1951 0.09878232 1952 -1.07216 1953 1.257622 1954 1.216247 1955 -1.112414 1956 -1.003297 1957 -0.2695266 1958 1.421213 1959 -0.2596079 1960 -0.9068556 1961 0.4073699 1962 -1.423306 1963 -0.1053394 1964 -1.013508 1965 -0.647383 1966 -1.315087 1967 0.2578095 1968 -0.6044093 1969 -1.575809 1970 0.5213847 1971 -0.5021495 1972 -1.097782 1973 -1.564314 1974 -0.3243538 1975 -0.763319 1976 0.9770731 1977 -0.3739019 1978 -1.197709 1979 -3.927912 1980 0.5648294 1981 1.992265 1982 -1.034292 1983 1.083687 1984 -1.272475 1985 -2.03587 1986 0.4892748 1987 0.9247249 1988 -0.5944996 1989 -1.288414 1990 0.1765232 1991 -0.4924444 1992 1.76016 1993 -1.962035 1994 -0.2469731 1995 1.639622 1996 0.4103704 1997 -0.4302233 1998 1.061422 1999 1.22342 2000 1.954149 2001 -1.217276 2002 0.7111537 2003 1.027702 2004 0.1267058 2005 1.115224 2006 1.566887 2007 -0.235509 2008 -0.5174115 2009 0.05824029 2010 -1.276425 2011 -0.5266449 2012 1.090346 2013 0.02937802 2014 -0.7007461 2015 1.671761 2016 1.824109 2017 0.4275142 2018 0.348385