1955  -9.10284  2.68021
1956  -7.58095  2.66767
1957  -7.76829  2.64586
1958  -3.3166  2.63143
1959  -5.51547  2.65378
1960  -3.87438  2.62898
1961  -2.16015  2.62517
1962  -0.978545  2.61198
1963  -2.57392  2.59951
1964  -3.82443  2.5874
1965  -3.69586  2.55925
1966  -3.16967  2.54322
1967  -4.40373  2.52006
1968  -6.47999  2.48065
1969  -5.92019  2.48138
1970  -4.26336  2.46616
1971  -2.58441  2.41873
1972  -1.59164  2.42438
1973  -1.02289  2.42885
1974  -1.38326  2.4617
1975  0.782474  2.47898
1976  -0.492708  2.44741
1977  0.0604232  2.44498
1978  -0.976221  2.43751
1979  -1.00859  2.41069
1980  3.88412  2.39652
1981  4.90199  2.40431
1982  3.81635  2.38904
1983  1.14654  2.38601
1984  3.14544  2.3961
1985  3.87411  2.36891
1986  3.82058  2.3693
1987  3.73594  2.34238
1988  6.14993  2.3518
1989  5.16938  2.36185
1990  6.04229  2.29457
1991  7.86637  2.30225
1992  6.36159  2.29444
1993  4.60379  2.28304
1994  5.97803  2.31549
1995  5.24835  2.29406
1996  8.3624  2.29855
1997  8.91344  2.29795
1998  8.072  2.28886
1999  10.2706  2.29862
2000  9.64741  2.31455
2001  12.8476  2.32866
2002  15.8881  2.33078
2003  18.3034  2.27819
2004  17.0795  2.20476
2005  16.6331  2.16091
2006  16.8649  2.15614
2007  15.5218  2.14506
2008  17.6373  2.15094
2009  19.0763  2.14622
2010  18.6377  2.14578
2011  19.0757  2.14782
2012  19.7186  2.14907
2013  21.4736  2.19507
2014  22.3769  2.20021
2015  24.0032  2.18696
2016  22.8409  2.1817
2017  25.3761  2.0975
2018  24.9089  2.208