# year    value 
 1900    -0.15 
 1901     0.51 
 1902    -0.33 
 1903    -0.28 
 1904     -0.7 
 1905    -0.57 
 1906     0.22 
 1907    -0.87 
 1908    -0.77 
 1909    -0.91 
 1910     0.42 
 1911    -0.37 
 1912    -0.65 
 1913    -0.34 
 1914     0.22 
 1915    -0.13 
 1916    -0.52 
 1917    -0.92 
 1918    -0.24 
 1919    -0.53 
 1920     0.31 
 1921     0.38 
 1922     0.14 
 1923    -0.65 
 1924     -0.5 
 1925     0.24 
 1926    -0.16 
 1927    -0.18 
 1928    -0.59 
 1929    -0.29 
 1930     0.35 
 1931    -0.26 
 1932    -0.29 
 1933    -0.51 
 1934     0.13 
 1935    -0.33 
 1936     -0.3 
 1937    -0.24 
 1938     0.63 
 1939        0 
 1940     0.18 
 1941     0.04 
 1942    -0.01 
 1943     0.08 
 1944     0.36 
 1945     0.13 
 1946     0.33 
 1947     0.31 
 1948     0.16 
 1949     -0.1 
 1950    -0.02 
 1951     0.11 
 1952    -0.11 
 1953      0.3 
 1954    -0.76 
 1955    -0.42 
 1956    -0.69 
 1957    -0.24 
 1958    -0.02 
 1959     0.38 
 1960    -0.69 
 1961     0.64 
 1962     0.35 
 1963     0.07 
 1964     -0.3 
 1965    -0.28 
 1966     0.14 
 1967     0.17 
 1968     0.75 
 1969    -0.44 
 1970    -0.24 
 1971    -0.26 
 1972     0.05 
 1973      0.4 
 1974     0.03 
 1975     0.31 
 1976    -0.35 
 1977        1 
 1978     0.25 
 1979     0.07 
 1980    -0.23 
 1981     0.92 
 1982     0.13 
 1983     0.42 
 1984     0.11 
 1985     0.23 
 1986     0.62 
 1987     0.11 
 1988     0.47 
 1989     0.88 
 1990     1.32 
 1991     0.52 
 1992     0.39 
 1993     0.46 
 1994     0.79 
 1995      0.7 
 1996    -0.12 
 1997     0.95 
 1998     1.12 
 1999     0.83 
 2000     1.66 
 2001     1.62 
 2002     1.01 
 2003     0.63 
 2004     1.21 
 2005     1.19 
 2006     1.31 
 2007      1.5 
 2008     1.68 
 2009     1.01 
 2010     1.04 
 2011     0.96 
 2012      1.8 
 2013        1 
 2014     1.47 
 2015     1.54 
 2016     2.04 
 2017     1.74 
 2018     1.67