Constraints on the neutral fraction across cosmic time. The solid and dashed colored boxes indicate our 1σ and 2σ constraints, respectively. Right: constraints obtained in this work, in the two redshift bins and with the two x_HI − L relations proposed. Left: existing constraints from the literature: McGreer et al. (2015), Greig et al. (2017), Greig et al. (2019), Davies et al. (2018), Mason et al. (2018), Mason et al. (2019), Wang et al. (2020), Yang et al. (2020a,b), Zhu et al. (2022), Bosman et al. (2022), Jin et al. (2023), Zhu et al. (2024). Some of the literature points have been slightly shifted in redshift, and the constraints of Greig et al. (2024) have been combined for improved clarity.