Self-normalised yield ratios of ${\rm K^0_S}$, $\Lambda$, and $\Xi$ in pp collisions at $\sqrt{s} = 13 \rm TeV$ in the high/low multiplicity and high/low $ZN$ selections (V0M+SPDClusters classes). The ratios are shown as a function of the average charged-particle multiplicity $\langle n_{\rm ch} \rangle$ (left) and the forward energy $\langle ZN \rangle$ (right), self-normalised to the minimum bias ($\rm INEL>0$) value. Statistical and total systematic uncertainties are shown by error bars and boxes, respectively.