y     x1 x2
    99   6.5  1
   125  11.0  1
   200  17.0  1
   550  37.0  1
   100   9.0  1
   250   6.0  2
   400  14.0  2
   475  18.0  2
   250  12.0  2
   670  26.0  2
   820  44.0  2
   325   8.0  2
   366  15.0  2
   325   9.0  2
   411   7.0  3
   580  14.0  3
   580  17.0  3
   580  16.5  3
   400  18.0  3
   640  22.0  3
   468   6.0  4
   668  22.0  4
   850  24.0  4
   825  27.0  4
   950  27.0  5
  1000  31.0  6
   780  12.0  6