Could you please explain what is "adequate amount of activity"?
There isn't a fixed number. However, if you take a look within the "Other languages/locations" section, you will find that there are threads which have much more activity/posts in comparison to the Ukranian one. The current top three are: Serbian, Pakistani, Slovenia with 1180+, 980+, 818+ posts respectively. In comparison, the Ukrainian one has 420+.