MDFs for bar (dashed line) and non-bar (solid line) stars in bins of the net angular momentum parameter in inertial frame (L_zi). The three vertical red lines, at [Fe/H]of −0.65, −0.5, −0.07, and +0.35 dex, are drawn to guide the location of main peaks in the MDFs, while the arrows in panel 5 and panel 7 highlight the change in the MDF peaks. For the non-bar population, the main MDF peak shifts from −0.65 dex, for the slowly non-rotating old bulge population, to −0.5 dex for the rotating thick-disc-dominated population.