# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000         0.0139014         0.0133694    
     0.700000           1.00000         0.0366366         0.0117853    
      1.00000           1.54000         0.0237009         0.0218891    
      1.54000           2.40000         0.0316436         0.0173093    
      2.40000           4.80000         0.0171598        0.00996688    
      4.80000           10.0000        0.00983068        0.00771086