Abundance ratios of the three elements involved. The data are from APOGEE DR17 and are binned and colour-coded according to the data density in each bin. The blue line represents the running median, computed assuming a bin size of 0.1 dex and an overlap of 0.025 dex, and the blue shaded area represents the related standard deviation. Left panel: [Mg/Fe] in the MW as predicted by REF MW model (black line) and by NEW MW model (white line) compared to APOGEE data. Middle panel: [Al/Fe] MW abundance for both models (same colour-coding as left panel). Right panel: [Mn/Fe] abundance for REF MW and NEW MW models (same colour-coding).