Dust-corrected metallicity [M/H]_tot as a function redshift for the GRB-selected galaxies. The small red data points show individual measurements, and the large red hexagons represent the H I-weighted means with redshift, where the error bars denote the redshift interval and 1σ dispersion, respectively. The best-fit relation [M/H]_tot(z) = (−0.21 ± 0.04)z − (0.47 ± 0.14) is shown as the solid black line, with the dark- and light-shaded gray regions indicating the 1 and 2σ confidence intervals. For comparison, we overplot the average dust-corrected metallicities of MW, LMC, and SMC sightlines and predictions from the compiled set of simulations from Yates et al. (2021b): the DM and MM from the L-Galaxies simulations (Henriques et al. 2020; Yates et al. 2021a), the EAGLE simulations (Crain et al. 2015; Schaye et al. 2015), and the IllustrisTNG-100 (Pillepich et al. 2018; Springel et al. 2018). Generally, all observations and simulations seem to find similar slopes of #x0394;log(O/H)/#x0394;z ≈ 0.1 − 0.3. However, only the L-Galaxies simulations are able to reproduce the lower average metallicities inferred from the GRB sightlines.