$p_{\rm T}$-differential per-event yield of prompt $\Xi_{\rm c}^0$ (left) and $\Xi_{\rm c}^+$ (right) baryons measured in the different multiplicity classes in pp collisions at $\sqrt{s}=13$ TeV at midrapidity ($|y| < 0.5$), along with the corresponding ratios to the multiplicity-integrated (INEL $>$ 0) class in the bottom panel. The values shown in the legend, denoted as $\langle {\rm d}N/{\rm d}\eta \rangle_{|\eta|< 0.5}$, correspond to the average charged-particle multiplicity at midrapidity for the respective multiplicity classes, as introduced in Table.2. The statistical and systematic uncertainties are shown as bars and open boxes, respectively. The shaded boxes indicate the uncertainty of the branching ratio.