Densest QGs are the oldest both as centrals and as satellites. We plot the running medians of the distance from the Σ1 ridgeline (black line in Figures 2 and 4; Equation (1)) as a function of stellar mass (M⋆) for old (﹩\gtrsim 4\,\mathrm{Gyr};﹩ red), intermediate (﹩\approx 2-4\,\mathrm{Gyr};﹩ yellow), and young (﹩\lesssim 2\,\mathrm{Gyr};﹩ blue) QGs in ZENS. The shaded bands show the 1σ error on the running medians. The dotted line indicates the median distance from the Σ1 ridgeline computed for all QGs. The thin solid black line indicates the Σ1 ridgeline at z = 0.37, i.e., for the quiescent populations existing ﹩\gtrsim 4\,\mathrm{Gyr}﹩ ago (see the text for details and references). The black and red lines agree, showing that the QGs quenched before 4 Gyr ago have not evolved significantly in zeropoint from then to now. The middle panel shows the median values of the running distances, collapsed over the stellar mass axis. At all masses between ﹩{10}^{10.0}-{10}^{11.5}\,{M}_{\odot }﹩, older QGs have higher central stellar mass densities than younger QGs. The right panel replots the central panel but now showing centrals and satellites separately. Within the errors, both populations show the same trend.