Relationship between GC mass and NS populations. Colours denote individual clusters as listed in legend of Fig. 2. The full dataset is given in Table 2. Top: initial mass of GCs vs the total number of NSs formed up to the present day. The dashed line shows the best-fit linear relation (slope = 9428.42 NSs per 10⁶M_⊙, R² = 0.87), with the shaded region representing the ±1436 NSs scatter around the fit. Bottom: current mass of GCs vs bound number of NSs. The dashed line shows the best-fit linear relation (slope = 95.29 NSs per 10⁵ M_⊙, R² = 0.11), with the shaded region representing the ±842 NSs scatter around the fit.