AGN fraction as a function of r, shown for low-mass (dashed line) and massive galaxies (solid line) at low redshift (in blue) and high redshift (in red). Each panel represents the AGN fraction in clusters of different mass M₅₀₀ range. High-redshift massive clusters are omitted due to their low abundance and thus high statistical uncertainty. The coloured bands represent the 68% confidence intervals obtained with binomial statistics (see Sect. 3). Central BCGs are excluded.