# year value 1880 -1.02 1881 -2.16 1882 0.23 1883 -1.65 1884 -0.49 1885 -0.8 1886 -1.42 1887 0.77 1888 -2.33 1889 -1.29 1890 -0.26 1891 0.21 1892 -1.89 1893 -2.81 1894 -1.24 1895 -1.87 1896 -1.84 1897 -1.48 1898 -0.93 1899 -1.75 1900 -1.39 1901 -0.41 1902 -2.03 1903 -0.89 1904 -0.29 1905 -0.18 1906 -1.11 1907 -0.74 1908 -1.35 1909 -0.75 1910 0.36 1911 -1.12 1912 -0.7 1913 -1.07 1914 0.09 1915 0.55 1916 -0.45 1917 -1.63 1918 -1.69 1919 -2.07 1920 0.37 1921 0.17 1922 -0.57 1923 1.04 1924 -0.03 1925 1.05 1926 0.66 1927 -0.2 1928 1.19 1929 0.94 1930 0.9 1931 0.13 1932 0.86 1933 -0.29 1934 1.26 1935 1.56 1936 -0.44 1937 2.64 1938 1.19 1939 0.45 1940 1.42 1941 -0.78 1942 0.49 1943 1.47 1944 2.02 1945 2.04 1946 -1.11 1947 0.15 1948 0.61 1949 -0.1 1950 -0.38 1951 -0.67 1952 0.38 1953 0.31 1954 -0.09 1955 0.34 1956 -0.88 1957 0.81 1958 -0.25 1959 0.62 1960 -0.03 1961 1.09 1962 0.98 1963 1.03 1964 0.39 1965 -0.52 1966 -2.34 1967 -0.08 1968 0.75 1969 -1.29 1970 0.59 1971 -0.59 1972 -0.79 1973 0.6 1974 -0.61 1975 0.15 1976 -0.16 1977 0.26 1978 0.79 1979 -1.68 1980 1.24 1981 2.48 1982 0.7 1983 0.94 1984 1.57 1985 -0.46 1986 1.18 1987 -0.53 1988 1.07 1989 1.83 1990 -0.33 1991 0.33 1992 1.05 1993 2.21 1994 -0.68 1995 2.59 1996 1.35 1997 0.53 1998 -0.14 1999 0.92 2000 1.93 2001 0.6 2002 1.3 2003 1.5 2004 1.76 2005 1.66 2006 1.43 2007 2.97 2008 2.63 2009 1.48 2010 0.85 2011 1.41 2012 2.8 2013 0.81 2014 2.18 2015 2.79 2016 4.22 2017 2.76 2018 3.79 2019 2.8