# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000        0.00861468         0.0144288    
     0.700000           1.00000         0.0309828         0.0121791    
      1.00000           1.54000         0.0421147         0.0109807    
      1.54000           2.40000              -NaN              -NaN    
      2.40000           4.80000         0.0116120        0.00867654    
      4.80000           10.0000         0.0114920        0.00422239