Ionizing-to-nonionizing observed flux ratio (f _LyC/f₁₅₀₀) _out in units of F_ν as a function of for high- and low-z galaxies. At high redshift, we only show measurements determined from stacks. LyC detections from Pahl et al. (2021) and Fletcher et al. (2019) at z ∼ 3 are plotted in black and blue symbols. Circles show detections and downward pointing triangles are 1σ upper limits that are color coded by sample (Pahl et al. 2021; Alavi et al. 2020; Bian & Fan 2020; Fletcher et al. 2019; Naidu et al. 2018; Grazian et al. 2017; Rutkowski et al. 2017; Japelj et al. 2017). The high-z data probe z ∼ 2.5 − 4, except for the study of Alavi et al. (2020) at z ∼ 1.3, and Bridge et al. (2010) at z ∼ 0.7. The low-z data from the present study (LzLCS and literature) are plotted in light gray and red, as in the previous figure.