PACS detection rate in the different redshift bins, increasing from left to right, for the low-L_X subsample (left) and for the total one (right). The GOODS fields are represented in the upper panels and COSMOS in the lower ones. AGN hosts are showed as coloured solid lines and circles, inactive galaxies are represented by black dotted lines and open boxes. 1σ uncertainties are derived through binomial statistics. Masses indicate the centre of each mass bin. Upper limits indicate cases where none of the galaxies is detected by PACS. Detection in all PACS bands is required.