Double ratios of \fzero to $\pi$ (left panel) and K$^{*}$(892)$^{0}$ (right panel) as a function of charged-particle multiplicity. The single ratio is divided by the ratio in INEL $>$ 0 events, which cancels correlated systematic uncertainty. Two curves show calculations from $\gamma_{S}$CSM  with two assumptions for the hidden strangeness of \fzero in the correlation volume of 3$\mathrm{d}V/\mathrm{dy}$.