(left) Parameter $n$ as a function of $x_{\rm T}$ for several $\pi^0$ (top) and $\eta$ (bottom) spectra ratios at different collision energies. (right) Scaled differential invariant cross section of $\pi^0$ (full markers) and $\eta$ (open markers) as a function of $x_{\rm T}$ at different collision energies from $\sqrt{s}= 0.9$ TeV to $\sqrt{s}= 13$ TeV.