# year    value 
 1900     0.05 
 1901     0.13 
 1902     0.14 
 1903    -0.05 
 1904    -0.53 
 1905     0.19 
 1906    -0.06 
 1907    -0.25 
 1908    -0.29 
 1909    -0.32 
 1910    -0.23 
 1911    -0.17 
 1912    -0.26 
 1913    -0.41 
 1914     0.05 
 1915     0.37 
 1916    -0.25 
 1917    -0.46 
 1918    -0.22 
 1919    -0.18 
 1920    -0.24 
 1921    -0.11 
 1922    -0.28 
 1923    -0.18 
 1924     0.09 
 1925    -0.11 
 1926     0.18 
 1927    -0.01 
 1928     0.02 
 1929    -0.27 
 1930    -0.11 
 1931     0.19 
 1932    -0.05 
 1933     -0.2 
 1934    -0.11 
 1935    -0.18 
 1936    -0.23 
 1937    -0.01 
 1938    -0.21 
 1939    -0.15 
 1940     0.03 
 1941      0.3 
 1942        0 
 1943     -0.3 
 1944     0.11 
 1945     0.04 
 1946    -0.16 
 1947     0.11 
 1948    -0.03 
 1949    -0.05 
 1950    -0.29 
 1951     0.09 
 1952        0 
 1953     0.03 
 1954    -0.22 
 1955    -0.24 
 1956    -0.35 
 1957     0.05 
 1958     0.08 
 1959    -0.02 
 1960     0.09 
 1961    -0.09 
 1962     0.02 
 1963     0.16 
 1964     -0.2 
 1965    -0.13 
 1966     0.21 
 1967    -0.17 
 1968    -0.04 
 1969     0.17 
 1970     0.08 
 1971    -0.29 
 1972     0.19 
 1973     0.22 
 1974    -0.08 
 1975     -0.2 
 1976    -0.18 
 1977      0.2 
 1978        0 
 1979     0.34 
 1980      0.3 
 1981     0.26 
 1982      0.3 
 1983     0.63 
 1984     0.17 
 1985     0.11 
 1986     0.26 
 1987     0.92 
 1988     0.38 
 1989     0.34 
 1990     0.39 
 1991     0.43 
 1992     0.33 
 1993     0.55 
 1994     0.24 
 1995     0.68 
 1996     0.47 
 1997     0.67 
 1998     1.07 
 1999     0.42 
 2000     0.49 
 2001     0.63 
 2002     0.88 
 2003     0.67 
 2004     0.65 
 2005     0.81 
 2006     0.78 
 2007     0.64 
 2008     0.51 
 2009     1.09 
 2010      0.9 
 2011     0.91 
 2012      0.8 
 2013     0.65 
 2014     1.05 
 2015     1.19 
 2016     1.14 
 2017      1.1 
 2018     0.91