Plot of the fractional rms dispersion in values of ratios between various strong lines for the 16 objects with two or more independent GMOS spectra. For virtually all of the objects with Hα flux ﹩\gt 2\times {10}^{-16}\,\mathrm{erg}\ {\mathrm{cm}}^{-2}\ {{\rm{s}}}^{-1}﹩, the fractional dispersion is ﹩\lesssim 20 \% ﹩.