Time evolution of the relative magnetic helicity H_V and volume threading helicity H_PJ for the ten ARs under study. Quantities for ARs productive of large eruptive and confined flares are shown in the left and right columns, respectively. Squares (bullets) indicate the solutions based on enhanced (standard) divergence freeness. The gray (light-blue) shaded areas mark the spread of H_V (H_PJ), and the solid-black (dashed-blue) curve indicate the respective average values of H_V (H_PJ). The vertical bar marks the impulsive flare phase.