# year value 1900 -0.55 1901 -0.55 1902 -0.87 1903 -0.67 1904 -0.42 1905 -0.7 1906 -0.42 1907 -0.44 1908 -0.81 1909 -0.44 1910 -0.21 1911 -0.32 1912 -0.25 1913 -0.08 1914 0.2 1915 -0.02 1916 -0.82 1917 -0.15 1918 -0.42 1919 0.02 1920 -0.33 1921 -0.23 1922 -0.3 1923 -0.68 1924 -0.43 1925 -0.64 1926 -0.16 1927 -0.33 1928 -0.05 1929 -0.44 1930 -0.18 1931 -0.45 1932 -0.26 1933 -0.22 1934 0.05 1935 -0.08 1936 -0.06 1937 -0.34 1938 -0.35 1939 0.11 1940 0.43 1941 0.54 1942 -0.26 1943 -0.44 1944 -0.05 1945 0.15 1946 -0.14 1947 0.1 1948 -0.29 1949 0.07 1950 0.02 1951 0.15 1952 -0.21 1953 -0.15 1954 -0.21 1955 -0.63 1956 -0.17 1957 -0.12 1958 0.17 1959 0.13 1960 -0.29 1961 -0.03 1962 0.25 1963 -0.01 1964 -0.37 1965 0.08 1966 -0.24 1967 -0.28 1968 0.25 1969 0.11 1970 0.09 1971 -0.09 1972 -0.08 1973 0.05 1974 0.11 1975 0.17 1976 -0.15 1977 0.29 1978 0.2 1979 0.52 1980 0.27 1981 0.2 1982 0.01 1983 -0.06 1984 -0.36 1985 0.64 1986 0.3 1987 0.51 1988 0.31 1989 0.15 1990 0.3 1991 0.35 1992 -0.09 1993 0.42 1994 0.41 1995 -0.14 1996 0.3 1997 0.43 1998 0.83 1999 0.59 2000 0.32 2001 0.48 2002 0.25 2003 0.52 2004 0.69 2005 0.7 2006 0.55 2007 -0.16 2008 0.36 2009 0.72 2010 0.18 2011 0.4 2012 0.34 2013 0.79 2014 0.91 2015 0.76 2016 0.59 2017 0.92 2018 0.25