Mask and observed normalized MDF for ALR (left) and AGR (right) in the R − Z range of 7 ≤ R ≤ 9 kpc and 0 ≤ | Z | ≤ 2 kpc. The survey histograms are in black, while GALAXIA and TRILEGAL histograms are in blue and red, respectively. Histograms are normalized by dividing the counts in each 0.1 dex bin by the total number of sources. The distributions in black line represent the observed MDF, while those in blue and red lines represent the mask MDF for GALAXIA and TRILEGAL, respectively. APOGEE and RAVE distributions are shown in the top and middle rows, respectively, and the LAMOST (left) and GES (right) in the bottom row. Quartile values for both distributions are given in each panel colour-coded according to the distribution. Indicated is also the giant-to-dwarf ratio for mask and observed samples of each survey for both models.