Centre-of-mass energy dependence of the high $p_{\rm T}^{\rm trig}$ plateau value of the charged-particle number density in the transverse region. The ATLAS, CDF, CMS and STAR data points were taken from the compilation reported by the STAR collaboration. Error bars represent statistical and systematic uncertainties summed in quadrature. The data are compared with a parametrisation of the form $s^{0.27}+0.14\log(s)$ .