# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000         0.0305641         0.0284918    
     0.460000          0.700000         0.0278022         0.0275696    
     0.700000           1.00000         0.0406945         0.0312324    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000         0.0677143         0.0292789    
      2.40000           4.80000         0.0533945         0.0431129    
      4.80000           10.0000              -NaN              -NaN