Kiel diagram of the full sample (contours; satisfying the initial query restrictions in log g <  3, [Fe/H] <  −1, (g − r)₀ >  0.2, S/N >  20, and respective cuts in the parameter errors) and the subset of halo giants (dots; after removal of metallicity-dependent CMD features and further pruning the metal-rich and -poor tails above −1.3 and below −1.8 dex) used for our statistical purposes.