Comparison between the measured and simulated R_FeII and values for the highest and lowest S/N bins used in Sect. 9.1.2. For clarity, each figure displays only one of the ten sets of spectra for that S/N. The values used to simulate the spectra (grey points) are connected to the corresponding best fit measurements (except for cases where either the broad Hβ or FeII components were not detected). For clarity, the figures do not show a small number of unphysically high R_FeII measurements.