[Mg/Fe]-[Fe/H] relation for the MW bulge. The left panel shows the distribution of APOGEE stars, while the right panel depicts the mass-weighted distribution obtained using the orbit superposition method within <3.5 kpc from the Galactic centre. The yellow lines show the distribution functions of [Mg/Fe] and [Fe/H] separately. The solid white line shows the border used to separate high- and low-α populations. The number of stars and stellar mass corresponding to the high- and low-α populations are marked in the panels. While the orbit superposition method assigns more mass to the metal-rich populations, both APOGEE data and the orbit superposition-based density reveal rather similar abundance distributions.