Bolometric luminosity evolution as inferred from OPTXAGNF best-fitting models to the 11 XMM-Newton observations. The left y-axis corresponds to the compact disc (R_out ≃ 15 R_g), and the right y-axis to the more extended one (R_out ≃ 140 R_g). The conversion between the two is a factor of ≃2.5. For each data point, we also show the corresponding XMM-Newton observation number (XMM1 to XMM11) as reference.