Particle ratios \simplekstarch/K~and \simplekstarZ/K, depicted as \rsimplekstar/K, in pp~, central \mbox{d--Au}~, central \mbox{p--Pb}~ and central \mbox{A--A}~ collisions as a function of \sqrtSnn. For the \mbox{d--Au} data, the numerator yield is derived from a combination of \simplekstarZ~and \simplekstarch~states. Bars represent the statistical uncertainties and boxes represent the systematic uncertainties. The points for \simplekstarZ~for \mbox{d--Au},\mbox{Cu--Cu}~and \mbox{p--Pb} collisions and for \simplekstarch~for pp collisions have been shifted horizontally for visibility. Red, blue and black lines represent the \simplekstarch/K ratio predicted with PYTHIA6-Perugia 2011~, PYTHIA8-Monash 2013~ and EPOS-LHC~, respectively.