# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000         0.0544644         0.0539685    
     0.700000           1.00000              -NaN              -NaN    
      1.00000           1.54000          0.171216         0.0503424    
      1.54000           2.40000          0.322057         0.0270071    
      2.40000           4.80000          0.113920         0.0134789    
      4.80000           10.0000         0.0219889         0.0121645