Distribution of times between the depletion event in $\widehat{[\mathrm{Fe}/\mathrm{H}]}(R_{\mathrm{birth}}$ = 0 kpc, τ) and the last major (blue; gas mass ratio > 25%) and minor/major (orange; gas mass ratio > 10%) mergers. A depletion event is defined as the projected central metallicity decreasing by at least 0.05 dex in 0.5 Gyr, smoothed over 2.5 Gyr. The majority of the time that the projected metallicity in the galactic central region decreases, the galaxy experienced a merger of at least 10% gas mass fraction within the previous 2 Gyr. This suggests that larger mergers potentially affect the evolution of the metallicity of the galactic center.