Average infrared SEDs of the sample binned by L _{O IV} /L _W2 (left panels) and of EW([O III])/EW(Hβ) (right panels) without (top panels) and with host-galaxy subtraction (bottom panels). The top 1/3, middle 1/3, and low 1/3 of the population are plotted as orange, dark green, and blue solid lines. As a comparison, we also show the spectral template of the normal quasar population (thick gray line) and the broadband SED template of the warm-dust-deficient (WDD) quasar population (light green dotted line) constructed in Lyu et al. (2017). All the templates are normalized at 3 μm with common mid-IR emission features denoted.