# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000        0.00500777        0.00549701    
     0.460000          0.700000        0.00387176        0.00474585    
     0.700000           1.00000        0.00751711        0.00316237    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000              -NaN              -NaN    
      2.40000           4.80000         0.0102035        0.00518544    
      4.80000           10.0000        0.00449424         0.0112579