# year value 1880 -0.64 1881 -2.4 1882 0.42 1883 -1.53 1884 -0.29 1885 -0.76 1886 -1.34 1887 0.84 1888 -2.29 1889 -1.13 1890 -0.33 1891 0.26 1892 -2.02 1893 -2.57 1894 -1.31 1895 -1.81 1896 -1.78 1897 -1.5 1898 -0.74 1899 -1.68 1900 -1.45 1901 -0.7 1902 -1.48 1903 -1.03 1904 -0.31 1905 0.13 1906 -1.19 1907 -0.75 1908 -1.02 1909 -0.97 1910 0.15 1911 -0.98 1912 -0.29 1913 -1 1914 0.31 1915 0.78 1916 -0.49 1917 -1.64 1918 -1.91 1919 -1.95 1920 0.63 1921 0.08 1922 -0.38 1923 0.98 1924 -0.06 1925 0.6 1926 1.17 1927 -0.06 1928 1.31 1929 1.16 1930 0.6 1931 0.26 1932 0.56 1933 -0.55 1934 1.06 1935 1.53 1936 -0.45 1937 2.39 1938 1.25 1939 0.39 1940 1.63 1941 -0.54 1942 0.7 1943 1.39 1944 2.06 1945 1.98 1946 -0.92 1947 0.02 1948 0.68 1949 -0.24 1950 -0.25 1951 -0.78 1952 0.21 1953 0.28 1954 -0.15 1955 0.25 1956 -0.79 1957 0.71 1958 -0.27 1959 0.63 1960 0.09 1961 1.26 1962 1.01 1963 1.36 1964 0.51 1965 -0.7 1966 -2.45 1967 -0.15 1968 0.84 1969 -1.44 1970 0.69 1971 -0.67 1972 -0.9 1973 0.45 1974 -0.63 1975 0.03 1976 -0.17 1977 0.56 1978 0.81 1979 -1.54 1980 1.29 1981 2.53 1982 0.56 1983 1.01 1984 1.46 1985 -0.18 1986 1.55 1987 -0.16 1988 1.05 1989 1.84 1990 -0.33 1991 0.41 1992 1.13 1993 2.13 1994 -0.5 1995 2.43 1996 1.37 1997 0.72 1998 0.1 1999 0.74 2000 1.84 2001 0.81 2002 1.16 2003 1.79 2004 1.75 2005 1.55 2006 1.43 2007 2.82 2008 2.46 2009 1.23 2010 1 2011 1.31 2012 2.57 2013 0.74 2014 2.42 2015 3.04 2016 4.24 2017 2.78 2018 3.78 2019 2.77