Differential (top) and cumulative (bottom) counts at 1.1 mm for different assumptions regarding image-plane source scale radii for low-significance sources: adopting (black filled circles, fiducial); assuming they are point sources (red filled diamonds); and adopting (blue filled squares). Our counts 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 Fujimoto et al. (2016) as green diamonds and Aravena et al. (2016) as green squares. 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 wavelength as S_1.1 mm = 1.29 × S_1.2 mm (following Hatsukade et al. 2016).