Year,Mean 1880,-0.2 1881,-0.12 1882,-0.1 1883,-0.21 1884,-0.28 1885,-0.32 1886,-0.31 1887,-0.33 1888,-0.2 1889,-0.12 1890,-0.37 1891,-0.24 1892,-0.27 1893,-0.3 1894,-0.31 1895,-0.21 1896,-0.15 1897,-0.11 1898,-0.28 1899,-0.16 1900,-0.09 1901,-0.15 1902,-0.27 1903,-0.35 1904,-0.44 1905,-0.28 1906,-0.23 1907,-0.4 1908,-0.43 1909,-0.47 1910,-0.42 1911,-0.44 1912,-0.35 1913,-0.34 1914,-0.16 1915,-0.11 1916,-0.34 1917,-0.4 1918,-0.26 1919,-0.22 1920,-0.27 1921,-0.21 1922,-0.28 1923,-0.24 1924,-0.28 1925,-0.21 1926,-0.1 1927,-0.21 1928,-0.21 1929,-0.36 1930,-0.15 1931,-0.09 1932,-0.17 1933,-0.29 1934,-0.14 1935,-0.2 1936,-0.15 1937,-0.03 1938,-0.03 1939,-0.03 1940,0.08 1941,0.12 1942,0.09 1943,0.13 1944,0.25 1945,0.12 1946,-0.04 1947,-0.05 1948,-0.09 1949,-0.09 1950,-0.18 1951,-0.07 1952,0.01 1953,0.08 1954,-0.13 1955,-0.15 1956,-0.2 1957,0.04 1958,0.07 1959,0.03 1960,-0.02 1961,0.05 1962,0.03 1963,0.06 1964,-0.2 1965,-0.1 1966,-0.05 1967,-0.02 1968,-0.07 1969,0.07 1970,0.02 1971,-0.09 1972,0.01 1973,0.15 1974,-0.07 1975,-0.02 1976,-0.11 1977,0.18 1978,0.07 1979,0.17 1980,0.27 1981,0.33 1982,0.13 1983,0.3 1984,0.15 1985,0.12 1986,0.19 1987,0.33 1988,0.41 1989,0.29 1990,0.44 1991,0.43 1992,0.23 1993,0.24 1994,0.32 1995,0.46 1996,0.35 1997,0.48 1998,0.64 1999,0.42 2000,0.42 2001,0.55 2002,0.63 2003,0.62 2004,0.55 2005,0.69 2006,0.63 2007,0.66 2008,0.54 2009,0.64 2010,0.71 2011,0.6 2012,0.63 2013,0.65 2014,0.74 2015,0.87 2016,0.99