Fractional phase contribution to [C II] luminosity as a function of galactic properties. From top to bottom: Contribution to L_[C II] from H I (orange), H₂ (dark pink), and H II (green) as a function of stellar mass, star formation rate, stellar metallicity, and H I mass at z = 10 (left panels) and 6 (right). The solid line displays the median values, and the shaded areas show the 1σ scatter. The stars represent the contribution from the three phases in bins with fewer than three galaxies. The [C II] emission mostly traces neutral atomic gas.