# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000         0.0432453        0.00490993    
     0.460000          0.700000         0.0523087        0.00652246    
     0.700000           1.00000         0.0452340        0.00881133    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000         0.0442352         0.0208748    
      2.40000           4.80000              -NaN              -NaN    
      4.80000           10.0000              -NaN              -NaN