# year value 1880 -1.83 1881 -0.94 1882 -0.58 1883 -2.49 1884 -0.12 1885 -1.02 1886 -0.78 1887 -1.92 1888 -0.28 1889 -0.98 1890 -1.38 1891 -0.25 1892 -0.18 1893 -1.3 1894 -0.27 1895 -1.8 1896 -0.91 1897 -0.45 1898 0.21 1899 -0.78 1900 0.46 1901 -0.85 1902 0.69 1903 -0.45 1904 -1.49 1905 -1.63 1906 -0.67 1907 -0.82 1908 -0.56 1909 -0.43 1910 -1.41 1911 -0.82 1912 -0.71 1913 0.1 1914 -0.15 1915 -1.18 1916 -0.41 1917 -0.31 1918 -0.29 1919 -0.4 1920 -0.4 1921 -0.95 1922 -0.73 1923 -0.53 1924 -1.4 1925 0.34 1926 0.51 1927 0.17 1928 -1.38 1929 -0.25 1930 0.43 1931 0.11 1932 0.34 1933 -0.31 1934 -0.31 1935 -0.32 1936 -0.22 1937 0.17 1938 -0.18 1939 0.43 1940 -0.56 1941 -0.28 1942 0.45 1943 0.6 1944 -0.03 1945 0.7 1946 -0.03 1947 -0.03 1948 0.07 1949 0.38 1950 0 1951 -0.73 1952 0.19 1953 0.1 1954 -0.07 1955 0.27 1956 -0.69 1957 -0.22 1958 0.24 1959 -0.5 1960 0.34 1961 0.12 1962 -0.1 1963 -0.01 1964 0.16 1965 -0.06 1966 -0.31 1967 -0.28 1968 0.16 1969 0.22 1970 0.27 1971 -0.5 1972 0.4 1973 0.55 1974 -0.65 1975 -0.33 1976 -0.13 1977 0.14 1978 0.09 1979 0.19 1980 0.46 1981 0.11 1982 0.12 1983 0.98 1984 0.4 1985 -0.03 1986 0.38 1987 0.58 1988 0.39 1989 0.82 1990 0.54 1991 0.29 1992 0.48 1993 0.2 1994 0.16 1995 0.7 1996 0.45 1997 0.27 1998 0.98 1999 0.5 2000 0.31 2001 0.55 2002 0.56 2003 0.72 2004 0.65 2005 0.72 2006 0.55 2007 0.81 2008 0.33 2009 0.57 2010 0.78 2011 0.44 2012 0.69 2013 0.82 2014 0.87 2015 0.56 2016 1.42 2017 1.16 2018 0.75 2019 0.66