# year value 1880 -0.31 1881 -0.19 1882 -0.25 1883 -0.04 1884 -0.41 1885 -0.69 1886 -0.36 1887 -0.56 1888 -0.7 1889 0.06 1890 -0.02 1891 -0.15 1892 -0.33 1893 -0.42 1894 -0.41 1895 -0.51 1896 -0.22 1897 -0.41 1898 -0.82 1899 -0.03 1900 -0.76 1901 -0.28 1902 0.02 1903 -0.5 1904 -0.09 1905 -0.24 1906 -0.22 1907 -0.58 1908 -0.42 1909 -0.5 1910 -0.4 1911 -0.51 1912 -0.31 1913 -0.44 1914 0.08 1915 -0.47 1916 -0.18 1917 -0.76 1918 -0.35 1919 0.21 1920 -0.23 1921 0.09 1922 -0.18 1923 0.07 1924 -0.85 1925 -0.27 1926 -0.41 1927 -0.39 1928 -0.13 1929 -0.39 1930 0.05 1931 -0.69 1932 -0.09 1933 -0.1 1934 -0.09 1935 0.09 1936 -0.3 1937 -0.27 1938 0.23 1939 -0.15 1940 -0.15 1941 -0.62 1942 -0.32 1943 -0.1 1944 -0.16 1945 0.18 1946 -0.33 1947 -0.02 1948 -0.5 1949 -0.35 1950 0.09 1951 -0.12 1952 -0.14 1953 0.19 1954 -0.15 1955 -0.3 1956 -0.55 1957 0.27 1958 0.06 1959 -0.48 1960 -0.22 1961 -0.1 1962 0.13 1963 -0.18 1964 -0.36 1965 -0.38 1966 0.15 1967 0.28 1968 0.03 1969 -0.03 1970 0.09 1971 -0.14 1972 0.05 1973 0.18 1974 0.36 1975 0.19 1976 -0.29 1977 0.02 1978 0.48 1979 0.17 1980 0.66 1981 0.57 1982 0.5 1983 0.22 1984 -0.23 1985 0.25 1986 0.28 1987 0.21 1988 0.24 1989 0.51 1990 0.33 1991 0.63 1992 0.15 1993 0.31 1994 0.46 1995 0.06 1996 0.37 1997 0.44 1998 0.68 1999 0.44 2000 0.27 2001 0.15 2002 0.25 2003 0.53 2004 0.32 2005 0.48 2006 0.11 2007 0.51 2008 0.44 2009 0.75 2010 0.76 2011 0.49 2012 0.49 2013 0.8 2014 0.54 2015 0.86 2016 0.77 2017 0.84 2018 1.13 2019 0.91