# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000        0.00549224        0.00595636    
     0.700000           1.00000        0.00951011        0.00480113    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000         0.0113314        0.00668888    
      2.40000           4.80000         0.0153647        0.00801481    
      4.80000           10.0000         0.0155316         0.0134097