Median highest position in the z-axis of the MW vs. median eccentricity, both in kpc (⟨Z_max⟩ vs. ⟨e⟩) for the five MMR subgroups (in the same colours as in Fig. 2) in the shape of 2D kernel density plots with their respective scatter markers. The Solar group parameters are shown in grey for comparison. No star has ⟨Z_max⟩ or ⟨e⟩< 0, but the images have been enlarged for better visualisation of the density curves. As a visual guide, the thin and thick disc thresholds are shown as black dashed and dot-dashed lines respectively.