x         y
   0       52.403
   0       45.864
   0       57.943
   0       54.797
   0       42.174
   20      64.029
   20      54.034
   20      72.921
   20      50.591
   20      64.948
   40      78.585
   40      63.586
   40      63.056
   40      68.515
   40      58.302
   60      77.775
   60      81.211
   60      80.923
   60      87.942
   60      91.031
   80      89.788
   80     105.386
   80      90.079
   80     103.182
   80      91.756
  100     117.913
  100     103.146
  100     105.366
  100      86.177
  100      94.694