CDFs and scaled PDFs for eight galaxies in the R_g-[Fe/H] parameter space. Dashed isodensity contours represent boundaries enclosing 5–95% of all data in 10% increments. White contours (dashed for 95% and solid for 99%, respectively) mark outer boundaries. Gray dots denote the distribution of GCs in each host galaxy. The hatched area highlights the depleted region of metal-poor GCs (A_DEP), while the shaded area in the MW panel indicates the outer non-depleted region (A_OUT; see Section 3.2). Red solid lines show the least-squares fitted metallicity gradient (Harris 2023; see Section 3.5). The CDFs are derived from the clustering results of the DBSCAN algorithm, with low-density regions excluded and classified as noise.