Top panel: unfolded XMM-Newton spectra of 2003 (in black) and 2017 (in green) compared to the stacked Swift/XRT spectra (in red and blue). In particular, the red spectrum is derived using all Swift/XRT datasets between 2010 and 2015, while the blue spectrum is derived using low flux state (log L_X <  24.92) Swift/XRT spectra during 2017. Bottom panel: ratio of the data points of the XMM-Newton observations, as well as the stacked Swift/XRT observations, to a simple model describing the continuum of the 2017 XMM-Newton observation. The color scheme is the same as in the top panel.