# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000              -NaN              -NaN    
     0.700000           1.00000         0.0300551         0.0260904    
      1.00000           1.54000         0.0298165        0.00700688    
      1.54000           2.40000         0.0181079        0.00549511    
      2.40000           4.80000         0.0207496        0.00435902    
      4.80000           10.0000         0.0220772        0.00533146