Star-formation history for the GB derived from the right panel of Fig. 14, which is corrected for visibility time and PNe birth rate. A dashed (blue) line, which is slightly shifted for a better presentation, shows the overplotted histogram from Bensby et al. (2013) for the bulge stars, excluding the most metal-poor objects. The open circles represent the points at which a constant SFH was backward-corrected for visibility time and PNe birth rate, as shown in Fig. 16.