# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000         0.0384468         0.0701221    
     0.700000           1.00000          0.197535         0.0552684    
      1.00000           1.54000          0.208911         0.0583720    
      1.54000           2.40000          0.382724         0.0312961    
      2.40000           4.80000          0.279789         0.0146270    
      4.80000           10.0000          0.189895         0.0112548