From top to bottom panel: observed flux in the 0.3−2.0 keV band, photon index of the primary continuum, column densities of the cold and the warm obscurer, and covering fractions of the cold and warm obscurer are shown as a function of time. The flux is plotted in units of 10^-11 erg s^-1 cm^-2. The column densities are plotted in units of 10²² cm^-2. The Modified Julian Day (MJD) correspondent to each observation is labeled on the horizontal axes, which we shrunk for display purpose. Black diamonds and red asterisks identify parameters measured with XMM-Newton and Chandra-LETGS, respectively. Error bars, when larger than the size of the plotting symbol, are also shown. Upper limits are plotted as an arrow. Crosses represent values that were kept frozen in the fits. In each panel, the dotted horizontal line indicates the parameter value derived in K14 for the coadded XM1−12 spectrum.