# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000        0.00979597        0.00812566    
     0.700000           1.00000         0.0195749        0.00849584    
      1.00000           1.54000        0.00953724        0.00745847    
      1.54000           2.40000              -NaN              -NaN    
      2.40000           4.80000        0.00921554         0.0101142    
      4.80000           10.0000              -NaN              -NaN