# year value 1880 -0.66 1881 0.16 1882 -0.57 1883 -0.49 1884 -0.55 1885 -0.2 1886 -0.43 1887 0.18 1888 -0.24 1889 0.65 1890 -0.22 1891 -0.37 1892 -0.68 1893 -0.2 1894 0.04 1895 -0.25 1896 -0.91 1897 -0.49 1898 -0.84 1899 -0.17 1900 0.1 1901 0.29 1902 -0.52 1903 -0.55 1904 -0.33 1905 -0.46 1906 0.21 1907 -0.3 1908 -0.39 1909 -0.66 1910 0 1911 -0.5 1912 -0.35 1913 -0.45 1914 0.04 1915 0.19 1916 -0.3 1917 -0.56 1918 -0.26 1919 -0.25 1920 -0.04 1921 -0.05 1922 -0.32 1923 -0.26 1924 -0.28 1925 0.18 1926 0.49 1927 -0.43 1928 -0.1 1929 0 1930 0.1 1931 -0.32 1932 -0.04 1933 -0.58 1934 0.19 1935 -0.31 1936 -0.19 1937 -0.37 1938 0.58 1939 0.22 1940 0.49 1941 0.32 1942 0.03 1943 0.42 1944 0.25 1945 0.23 1946 0.13 1947 0.71 1948 0.24 1949 0.15 1950 -0.04 1951 -0.29 1952 0 1953 0.34 1954 -0.28 1955 -0.63 1956 -0.38 1957 -0.28 1958 0.17 1959 0.2 1960 -0.26 1961 0.23 1962 0.13 1963 0.03 1964 -0.2 1965 -0.1 1966 -0.06 1967 0.17 1968 0.31 1969 0.17 1970 -0.11 1971 -0.16 1972 0.1 1973 0.26 1974 0.06 1975 0.17 1976 -0.43 1977 0.26 1978 0.4 1979 0.12 1980 0.03 1981 0.88 1982 0.09 1983 0.34 1984 0.32 1985 0.12 1986 0.29 1987 0.13 1988 0.42 1989 0.76 1990 1.11 1991 0.34 1992 0.58 1993 0.59 1994 0.79 1995 0.49 1996 0.41 1997 1.02 1998 1.07 1999 0.48 2000 1.26 2001 1.16 2002 1.17 2003 0.81 2004 1.18 2005 1.14 2006 0.76 2007 1.28 2008 1.42 2009 1.15 2010 0.89 2011 0.97 2012 1.12 2013 1.14 2014 1.51 2015 1.58 2016 1.91 2017 1.71 2018 1.83 2019 1.64