Particle yield ratio of \fzero to K$^{*}$(892)$^{0}$ as a function of charged-particle multiplicity. Vertical lines and boxes around data points represent statistical and systematic uncertainties, respectively. Two curves show calculations from $\gamma_{S}$CSM  with two assumptions for the hidden strangeness of \fzero in the correlation volume of 3$\mathrm{d}V/\mathrm{dy}$.