Comparison of ${\rm d}\nch$/${\rm d}\eta$ vs. $\eta$ measurements between the various centre-of-mass energies considered in this study: INEL (left), NSD (middle), and INEL$>$0 (right). The lower parts of the figures show the ratios of data at energies indicated to the data at 0.9 TeV, with corresponding colours. Systematic uncertainties are indicated as coloured bands.