First row: maximum contamination to the bulge CMDs from stars with proper motions consistent with belonging to the foreground population. Second row: ratio of foreground to background stars. Third row: maximum of the i₀ distribution (for i₀ > 17). Fourth Row: ratio of blue to red stars, when only stars with i₀ ≤ i_0, max − 3σ_i are considered. All the plots are shown as a function of Galactic coordinates, for the bulge fields shown in Fig. 1.