Mean νL_ν(60   μm) (L₆₀) vs. L_AGN of X-ray selected AGNs in 5 different redshift bins from the local Universe to z = 2.5. The colored data points are combinations of mean measurements in 3 PEP fields: GOODS-N/S and COSMOS, while the black data points come from our analysis of the SWIFT-BAT sample. The solid colored lines are functional fits to the mean measurements, as described in Sect. 4.1.1. The dashed line is the correlation line shown by AGN-dominated systems in Netzer (2009). The shaded region corresponds to the approximate 1σ range exhibited by empirical pure-AGN SEDs. At low redshifts, a strong change in the mean trend exists as a function of L_AGN, which disappears at high redshifts. The mean L₆₀ of low-luminosity X-ray AGNs increases monotonically with redshift, mirroring the increase in the mean SFR of massive galaxies across redshift.