# year    value 
 1900    -0.07 
 1901    -0.45 
 1902     -2.3 
 1903    -0.25 
 1904     0.07 
 1905     -0.3 
 1906    -0.12 
 1907    -0.47 
 1908    -0.68 
 1909     0.05 
 1910    -0.58 
 1911     0.35 
 1912    -0.66 
 1913    -0.85 
 1914    -0.11 
 1915    -0.87 
 1916      0.2 
 1917    -0.44 
 1918    -0.12 
 1919    -0.28 
 1920    -0.44 
 1921     0.17 
 1922     0.01 
 1923     1.29 
 1924     1.17 
 1925     0.38 
 1926     0.69 
 1927    -0.39 
 1928     0.21 
 1929     0.77 
 1930      0.3 
 1931     1.25 
 1932    -0.01 
 1933    -0.47 
 1934     1.02 
 1935    -0.09 
 1936     0.38 
 1937     1.37 
 1938     1.69 
 1939     0.35 
 1940     0.45 
 1941        0 
 1942     0.26 
 1943     1.74 
 1944     1.18 
 1945     0.29 
 1946    -0.12 
 1947     1.57 
 1948     1.34 
 1949     0.56 
 1950     0.21 
 1951     0.99 
 1952    -0.21 
 1953     0.49 
 1954     0.85 
 1955    -0.11 
 1956    -1.16 
 1957     -0.4 
 1958    -0.19 
 1959     0.62 
 1960    -0.39 
 1961     0.06 
 1962     0.39 
 1963     0.22 
 1964    -0.37 
 1965    -0.49 
 1966    -0.36 
 1967     1.19 
 1968    -0.79 
 1969     0.29 
 1970     0.19 
 1971     0.49 
 1972    -1.08 
 1973     0.39 
 1974    -0.82 
 1975     0.08 
 1976    -0.24 
 1977     0.12 
 1978     0.21 
 1979        0 
 1980    -0.02 
 1981     1.25 
 1982    -0.98 
 1983     0.94 
 1984    -0.25 
 1985     0.73 
 1986     0.17 
 1987    -0.17 
 1988     0.34 
 1989    -0.16 
 1990    -0.53 
 1991     1.05 
 1992    -1.33 
 1993     0.06 
 1994     0.37 
 1995     1.28 
 1996     0.79 
 1997     1.13 
 1998     0.25 
 1999     0.73 
 2000     0.75 
 2001     1.17 
 2002     1.15 
 2003     1.73 
 2004     1.16 
 2005     2.73 
 2006     1.38 
 2007     2.27 
 2008     1.72 
 2009     1.42 
 2010     2.41 
 2011     2.19 
 2012     1.89 
 2013     1.56 
 2014     1.11 
 2015      1.7 
 2016     2.47 
 2017     1.99 
 2018     2.14