Total number of galaxies observed (black line) and detected (blue line) in H i, either clearly or marginally, per 0.5 wide bin in absolute z-band magnitude, M_z, together with the overall detection percentage per bin (green line). We observed 130–165 objects per half-magnitude bin in M_z over the range of − 23 <M_z< − 16.5 mag (the target number was 150), and observed all objects known from the DR5 in the least-filled bins.