# year value 1901 -4.701211 1902 -0.04780915 1903 -1.037838 1904 -0.8287089 1905 -1.94955 1906 -1.236888 1907 -3.020647 1908 -0.9902377 1909 -3.082054 1910 0.3444724 1911 -0.8587735 1912 0.7446977 1913 -0.7498599 1914 -1.693611 1915 -0.3509349 1916 1.24523 1917 -1.818062 1918 -1.564257 1919 -0.1150147 1920 0.7794849 1921 0.451521 1922 -1.795498 1923 -0.3815652 1924 -2.298067 1925 0.5030912 1926 -0.198551 1927 -0.9508494 1928 -0.3674424 1929 -4.283432 1930 0.1405239 1931 -1.145726 1932 -2.435117 1933 -1.353517 1934 -2.313635 1935 -0.3727697 1936 0.2751915 1937 -0.02102953 1938 -1.441609 1939 -0.4009035 1940 -3.667875 1941 -3.141534 1942 -4.129949 1943 -0.1614253 1944 -0.7248599 1945 -2.205875 1946 -0.5411289 1947 -3.728903 1948 0.1050021 1949 -0.3289532 1950 -0.03077686 1951 -0.02538461 1952 -1.344124 1953 -1.796057 1954 -2.278185 1955 0.3059375 1956 -1.876212 1957 -0.1940987 1958 -0.1084932 1959 -0.1444683 1960 -0.1435532 1961 0.3026396 1962 -0.65697 1963 -4.710338 1964 -2.318267 1965 -1.630484 1966 0.3236063 1967 -0.708991 1968 -1.247534 1969 -1.865232 1970 -1.876365 1971 -1.137514 1972 0.3544017 1973 -0.7608043 1974 0.8229643 1975 1.030876 1976 -0.2983691 1977 0.2234586 1978 -0.7852142 1979 -0.9581845 1980 0.1523477 1981 -2.226012 1982 -1.138955 1983 -0.1412247 1984 -0.9238975 1985 -2.518817 1986 -1.216776 1987 -1.787001 1988 1.076534 1989 0.6194078 1990 1.400291 1991 -1.539144 1992 -0.5958141 1993 -0.1112839 1994 0.8519282 1995 0.981342 1996 -0.9006 1997 0.08692048 1998 1.531972 1999 -0.7994723 2000 -0.1355783 2001 1.240457 2002 -0.1626389 2003 -0.9988305 2004 -0.1939738 2005 -1.178258 2006 -1.897595 2007 2.494531 2008 1.01043 2009 -0.8671972 2010 -1.166418 2011 -0.6958476 2012 -0.832517 2013 -0.7870918 2014 1.983488 2015 0.6778787 2016 1.988801 2017 -0.003639658 2018 0.05536611