Distribution of total absorbing column density for each model. For sources best fit with a single power law or soft excess, this corresponds to the column density measured in the ztbabs component. For sources best fit with a warm absorber, this corresponds to the sum of the column densities from the ztbabs model and the XSTAR grid, and for sources best fit with neutral partial covering, this corresponds to the sum of the column densities measured from the ztbabs and zpcfabs components. Sources best fit with soft excesses are shown in red, sources best fit with warm absorbers are shown as blue dash-dot lines, and sources best fit with partial covering are shown as orange dashed lines. The typical error bar is shown in black.