The distributions of $\dndeta$ for the $\inels$ event class are normalised to the $\inelsss$ (left) and $\inelss$ (right) event classes using PYTHIA 8 with the Monash 2013 tuning in pp collisions at $\cms = 13$ TeV . The bottom panels show the ratio of $\dndeta$ for the $\inelsss$ (left) and $\inelss$ (right) event class between ALICE and ATLAS (left) and between ALICE and CMS (right), respectively.