# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000         0.0805683         0.0374267    
     0.460000          0.700000          0.140113         0.0278064    
     0.700000           1.00000         0.0646508         0.0270626    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000              -NaN              -NaN    
      2.40000           4.80000              -NaN              -NaN    
      4.80000           10.0000         0.0498552         0.0273875