# year value 1901 -1.916433 1902 2.801848 1903 1.631727 1904 1.902395 1905 0.8291194 1906 1.586212 1907 -0.2239981 1908 1.727536 1909 -0.3918984 1910 3.210024 1911 1.984322 1912 3.414576 1913 2.049127 1914 0.9886808 1915 2.581788 1916 4.100513 1917 0.9148664 1918 1.240323 1919 2.693532 1920 3.567762 1921 3.279663 1922 0.904743 1923 2.506952 1924 0.4244426 1925 3.28159 1926 2.636881 1927 1.918313 1928 2.229141 1929 -1.536265 1930 2.924978 1931 1.716272 1932 0.3524934 1933 1.390691 1934 0.391074 1935 2.520392 1936 3.144563 1937 2.632256 1938 1.476945 1939 2.424089 1940 -1.16773 1941 -0.3310342 1942 -1.495577 1943 2.585985 1944 2.092549 1945 0.6592184 1946 2.170725 1947 -1.079054 1948 2.979426 1949 2.440534 1950 2.672821 1951 2.94443 1952 1.576794 1953 1.106788 1954 0.1754093 1955 2.986234 1956 0.8612018 1957 2.611948 1958 2.664992 1959 2.585889 1960 2.683797 1961 3.13625 1962 2.069391 1963 -2.165716 1964 -0.004810552 1965 1.148439 1966 3.190947 1967 2.20501 1968 1.621946 1969 0.8362812 1970 0.8432691 1971 1.733315 1972 3.039157 1973 2.024838 1974 3.666242 1975 3.885504 1976 2.31976 1977 3.161911 1978 1.940502 1979 1.802691 1980 2.909927 1981 0.6912286 1982 1.430138 1983 2.83024 1984 1.968319 1985 -0.0569145 1986 1.567555 1987 0.780018 1988 3.960307 1989 3.341373 1990 4.185598 1991 1.260917 1992 2.22504 1993 2.502762 1994 3.772391 1995 3.894601 1996 1.56948 1997 2.507577 1998 4.401749 1999 1.934279 2000 2.763838 2001 4.12058 2002 2.643681 2003 1.569678 2004 2.591363 2005 1.633153 2006 0.9066911 2007 5.39544 2008 3.78699 2009 1.993656 2010 1.724425 2011 1.991425 2012 2.091318 2013 2.118342 2014 4.833761 2015 3.564266 2016 4.80532 2017 2.553034 2018 3.049227