# year    value 
 1900    -0.44 
 1901      0.4 
 1902     -0.7 
 1903    -0.53 
 1904    -0.67 
 1905    -0.48 
 1906    -0.53 
 1907    -1.01 
 1908    -1.03 
 1909    -0.77 
 1910    -0.51 
 1911     -1.6 
 1912    -0.37 
 1913    -0.06 
 1914    -1.57 
 1915    -0.66 
 1916     0.47 
 1917    -0.57 
 1918    -1.21 
 1919    -1.27 
 1920    -0.79 
 1921    -1.39 
 1922    -0.93 
 1923    -1.27 
 1924    -1.54 
 1925    -0.42 
 1926    -0.24 
 1927    -0.58 
 1928    -0.79 
 1929     -0.3 
 1930    -1.09 
 1931    -0.99 
 1932    -0.03 
 1933    -0.26 
 1934     -1.4 
 1935    -1.14 
 1936    -0.18 
 1937    -0.66 
 1938    -0.02 
 1939    -0.46 
 1940    -0.82 
 1941    -0.29 
 1942     0.02 
 1943    -0.22 
 1944     0.85 
 1945     0.65 
 1946     0.19 
 1947    -0.29 
 1948      0.1 
 1949     -0.6 
 1950    -0.71 
 1951     0.24 
 1952    -0.38 
 1953     0.29 
 1954    -0.23 
 1955    -0.16 
 1956    -0.45 
 1957    -0.26 
 1958     0.05 
 1959    -0.08 
 1960    -0.19 
 1961     0.23 
 1962     0.42 
 1963    -0.13 
 1964    -0.41 
 1965     0.17 
 1966    -0.09 
 1967    -0.09 
 1968     0.14 
 1969      0.5 
 1970     0.28 
 1971     0.22 
 1972     0.12 
 1973    -0.39 
 1974    -0.35 
 1975    -0.24 
 1976    -0.06 
 1977     0.36 
 1978     0.33 
 1979    -0.01 
 1980    -0.07 
 1981    -0.02 
 1982     0.45 
 1983     0.34 
 1984     0.38 
 1985     0.28 
 1986     0.23 
 1987     0.79 
 1988     0.45 
 1989     0.22 
 1990     0.49 
 1991     0.33 
 1992     0.11 
 1993     0.17 
 1994     0.84 
 1995     0.65 
 1996     0.35 
 1997     1.16 
 1998     0.43 
 1999      0.5 
 2000     0.25 
 2001      0.4 
 2002      0.8 
 2003     0.83 
 2004      0.7 
 2005     0.27 
 2006     0.94 
 2007     0.41 
 2008     0.74 
 2009     0.92 
 2010     0.47 
 2011     0.82 
 2012     1.15 
 2013      0.6 
 2014     1.16 
 2015     1.02 
 2016     0.77 
 2017     0.66 
 2018     0.97