Differential (top) and cumulative (bottom) counts at 1.1 mm compared to ALMA results and galaxy formation model predictions from the literature. Our counts (large black filled circles) correspond to median values combining all models for all cluster fields. Error bars indicate the 16th and 84th percentiles, adding the scaled Poisson confidence levels for 1σ lower and upper limits respectively in quadrature. Arrows indicate 3σ upper limits for flux densities having zero median counts and non-zero values at the 84th percentile. We show previous results reported by Ono et al. (2014) as red crosses, Carniani et al. (2015) as blue squares, Fujimoto et al. (2016) as green diamonds (with their Schechter fit shown as a black dashed line), Oteo et al. (2016) as red triangles, Hatsukade et al. (2016) as blue crosses, Aravena et al. (2016) as green squares, Umehata et al. (2017) as red diamonds and Dunlop et al. (2017) as a black solid curve. We show number counts predicted by the galaxy formation models from Cowley et al. (2015, orange line), Béthermin et al. (2017, cyan line) and Schreiber et al. (2017, magenta line). We scale the counts derived at other wavelengths as S _1.1 mm = 1.29 × S _1.2 mm and S_1.1 mm = 1.48 × S _1.3 mm (following Hatsukade et al. 2016).