Projections of the rest-frame EW space spanned by EW₀(He II), EW₀(O III), EW₀(C III), EW₀(C IV) and EW₀(Lyα) from the collection of UV emission line measurements from the literature plotted throughout this paper. The bottom panels reproduce the corresponding panels from Figure 10 and the top right panel reproduces the top right panel of Figure B.2. All panels exclude the MUSE measurements presented in this paper, but assign different symbols to the literature data included in Table C.1 according to the legend at the top. The points are color coded according to redshift and 3σ limits are indicated by the gray arrows. The diagonal curves correspond to the 10:1, 3:1, 1:1, 1:3, and 1:10 relations.