# year    value 
 1900    -0.55 
 1901    -0.15 
 1902    -0.73 
 1903    -0.47 
 1904     -0.4 
 1905    -0.57 
 1906     0.16 
 1907    -0.51 
 1908    -0.05 
 1909     -0.2 
 1910    -0.39 
 1911    -0.08 
 1912     -0.7 
 1913    -0.34 
 1914     -0.2 
 1915     0.28 
 1916    -0.24 
 1917    -0.22 
 1918    -0.85 
 1919    -0.17 
 1920     0.04 
 1921     0.11 
 1922    -0.06 
 1923     0.19 
 1924    -0.34 
 1925    -0.28 
 1926    -0.29 
 1927     0.43 
 1928    -0.28 
 1929    -0.67 
 1930      0.1 
 1931     0.31 
 1932     0.12 
 1933    -0.36 
 1934    -0.19 
 1935    -0.05 
 1936     0.61 
 1937     0.16 
 1938      0.3 
 1939    -0.02 
 1940     0.11 
 1941     0.29 
 1942    -0.14 
 1943     0.14 
 1944    -0.36 
 1945     0.12 
 1946    -0.32 
 1947    -0.46 
 1948     0.02 
 1949    -0.73 
 1950    -0.46 
 1951    -0.23 
 1952    -0.14 
 1953     0.49 
 1954     0.51 
 1955    -0.22 
 1956    -0.27 
 1957     0.42 
 1958     0.02 
 1959      0.1 
 1960     0.56 
 1961      0.2 
 1962     0.08 
 1963    -0.28 
 1964    -0.15 
 1965    -0.49 
 1966      0.1 
 1967    -0.04 
 1968    -0.38 
 1969    -0.09 
 1970    -0.27 
 1971      0.2 
 1972    -0.29 
 1973     0.48 
 1974     0.28 
 1975     0.22 
 1976     -0.2 
 1977      0.4 
 1978    -0.79 
 1979    -0.35 
 1980      0.1 
 1981     0.39 
 1982    -0.19 
 1983     0.18 
 1984     0.29 
 1985     0.02 
 1986    -0.33 
 1987    -0.29 
 1988     0.63 
 1989      0.5 
 1990     0.71 
 1991     0.92 
 1992    -0.38 
 1993      0.6 
 1994     0.48 
 1995     0.64 
 1996    -0.02 
 1997     0.49 
 1998      1.1 
 1999     0.27 
 2000     0.53 
 2001     1.05 
 2002     0.97 
 2003     1.11 
 2004     0.68 
 2005     1.05 
 2006     0.84 
 2007     1.18 
 2008      0.6 
 2009     0.57 
 2010     0.94 
 2011     0.95 
 2012     1.01 
 2013     1.19 
 2014     0.77 
 2015     0.57 
 2016     1.67 
 2017     0.82 
 2018     0.85