Comparison of the plage areas derived here (black) to other published series based on the same datasets. (a): Ermolli et al. (2009a, yellow) and Ermolli et al. (2009b, red) for Ar data; (b): Chatterjee et al. (2016, blue), Priyal et al. (2017, red), and Singh et al. (2018, green) for Ko areas in disc fractions; (c): Ermolli et al. (2009b, red), Kuriyan et al. (1982, yellow), and Tlatov et al. (2009, blue) for Ko areas in fractions of a hemisphere; (d): Bertello et al. (2010, yellow), Ermolli et al. (2009b, red), Foukal (1996, green), Tlatov et al. (2009, blue), and SGD (pink) for MW data; (e): SGD (pink) for MM data. The curves are annual median values. All panels except (b) are in fractions of hemisphere corrected for projection effects. The numbers under the curves denote the conventional SC numbering.