OBS    Y    X1  X2
   1  457.7  17  27
   2  568.2  22  27
   3  452.8  16  24
   4  783.7  34  23
   5  629.4  30  21
   6  216.9  13  17
   7 1014.2  31  32
   8  471.6  25  19
   9  266.4  32  11
  10  243.3  15  11
  11  278.0  18  15
  12  354.6  12  27
  13  534.2  32  17
  14  374.2  26  16
  15  441.1  18  21
  16  762.7  31  22
  17  702.8  23  33
  18  582.6  30  19
  19  590.4  34  19
  20  131.6  16  13
  21  415.0  33  11
  22  606.3  28  21
  23  628.7  20  31
  24  130.3  14  11
  25  359.6  34  12
  26  438.2  14  29
  27  417.9  27  15
  28  332.7  21  17
  29  626.6  29  23
  30  575.2  16  34
  31  641.9  27  24
  32  448.5  26  15
  33  536.9  21  24
  34  742.2  30  25
  35  539.6  19  29
  36  516.8  19  25
  37  791.2  27  29
  38  516.9  15  31
  39  493.8  30  18
  40  366.3  32  12
  41  634.6  24  23
  42  194.4  13  19
  43  734.5  28  26
  44  432.9  26  16
  45  362.7  15  26
  46  231.4  11  16
  47  442.4  27  17
  48  538.5  22  28
  49  365.6  29  10
  50  315.9  17  19