Depletion timescale as a function of redshift. The red filled circles represent the z-GAL sources, including the Pilot Programme. The small red symbol and error bar in the bottom-right corner represent the typical uncertainty on τ_dep. The grey shaded area is the trend found by Saintonge et al. (2013). The different lines represent the trends found by Tacconi et al. (2020) for MS galaxies (δ_MS = ±0.6 dex, black solid line), starburst galaxies (δ_MS > 0.6 dex, blue dashed line), extreme starbursts (δ_MS > 1.2 dex, purple dotted line), and below-MS galaxies (δ_MS < 0.4 dex, red long-dashed line). The collection of data from the literature includes the same data as in Fig. 10 (see references in the caption).