Comparison of histogram of the NG detection rate multiplied by the square of the average cometocentric distance (red bars), with the monthly averages of the gas production rate Q (normalised to H₂O) calculated from the NG data (blue dots), the water production rate from Hansen et al. (2016, Fig. 9) (green squares), the ground-based dust brightness observations of Snodgrass et al. (2016) (yellow diamonds), and the heliocentric distance (grey dashed line).