# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000         0.0100710        0.00244655    
     0.460000          0.700000              -NaN              -NaN    
     0.700000           1.00000        0.00902106        0.00288016    
      1.00000           1.54000        0.00362035        0.00429428    
      1.54000           2.40000              -NaN              -NaN    
      2.40000           4.80000              -NaN              -NaN    
      4.80000           10.0000         0.0132400        0.00762411