Notes. Columns: (1) type of sample, (2) the number of elements in the sample, (3) detection rate of NH₂D in %, (4) deuterium fractionation, (5) effective spatial resolution of the NH₂D observations, (6) effective spatial resolution of the NH₃ observations, and (7) article reference. The two resolutions in Pillai et al.’s work correspond to the two studied clouds. In the work of Wienen et al., the three NH₂D resolution values correspond to measurements done with the Mopra telescope at 86 GHz, and with the IRAM telescope for 86 GHz and 110 GHz, respectively. The two NH₃ values correspond to measurements made with the Effelsberg telescope (Wienen et al. 2012) and with the Parkes 64 m telescope (Wienen et al. 2018), respectively. The values for both NH₂D and NH₃ spatial resolutions were calculated for the median distance of 4 kpc of the ATLASGAL catalogue. Busquet et al. (2010) used the VLA NH₃ measurements of Palau et al. (2007), and Galloway-Sprietsma et al. (2022) used the NH₃ measurements of Keown et al. (2017), therefore we list the spatial resolution of these datasets in the respective column. The distances used to calculate the spatial resolutions: 7.4 kpc and 3.4 kpc for Pillai et al. (2011), a median distance of 4 kpc for Wienen et al. (2021), 2 kpc for (Busquet et al. 2010), 1.3 kpc for Li et al. (2021), and 350 pc for Galloway-Sprietsma et al. (2022).