Colour map showing the average ${\overline{\sigma }}_{[\mathrm{O}\mathrm{I}\mathrm{I}\mathrm{I}]}$ values for the (a) low redshift (0.02 < z < 0.4) and (b) high redshift (0.4 < z < 0.8 sample in bins of L_1.4 GHz and L_[O III]. The colour of each bin represents the average velocity dispersion in that bin. The number of sources (the bin size) is mentioned at the top of each bin. Fraction of sources with disturbed [O III] are mentioned below the bin size, only for bins that had at least one disturbed source.