Efficiency-corrected log N − log P diagram for CGRO/BATSE from Stern et al. (2001) in black. The log N − log P of GBM is shown in green, adjusted to the one of CGRO/BATSE by multiplying by a constant whose value is obtained by minimising the χ² between the two histograms over the grey shaded region. The black dashed vertical line represents the N^pk cut to avoid biases due to faint flux incompleteness for our spectral constraint.