Sample selection schema. (I) Distance from the Galactic midplane (Z) vs the galactocentric radius (R) distribution of the parent inner-galaxy sample. The green (RPM) and black (RVS) colours represent the two spectroscopic sources. The background shows the 2D density distribution for the full RVS data, which is mostly concentrated at the solar neighbourhood. The red stars represents the current position of the Sun. (II) Z vs R for the bulge sample stars [Total (9661) = RPM(6211) + RVS (3450) ] confined to within 5 kpc. Unless otherwise stated, “bulge sample” refers to this group. The fraction of stars that are in the bulge sample from the parent inner-galaxy sample are also shown. (III) Similar to panel (I), but for stars that do not remain confined within 5 kpc.