Comparison of the redshift evolution of the line densities of O Iλ1302, C IIλ1334, Si IIλ1526, Mg IIλ2796, C IVλ1548, and Si IVλ1393. The highest redshift data points for each of the coloured curves represent the NIRSpec analyses in this work, extending from the lower-redshift line densities from O I (Becker et al. 2019), Si II and C II from the catalogue in Davies et al. (2023b), C IV (D’Odorico et al. 2022; Davies et al. 2023a), Si IV (D’Odorico et al. 2022), and Mg II (Chen et al. 2017).