Histograms of the extracted photometric magnetic activity level, log ⟨ S_{ph,k = 5} ⟩ for the full sample of stars for which we have retrieved a P_rot (grey), hot (red), dwarf (blue), and subgiant stars (green) as defined in Fig. 3. For reference, the activity of the Sun (166.1 ± 2.6 ppm) is also shown. The vertical dashed lines enclose the solar magnetic-activity range (from 89 to 258.5 ppm). The solar values are colour-coded as in Fig. 4.