Not sure how useful that column is as the estimate is manually guessed by who ever updates the Language entry row, so usually the translator who would have the best idea of approximately how much translation has been done, so take your best guess please.
For tracking purposes please raise a feature request for the Language to be be enabled.
Can I check have you manually enabled Links to wiki manual in your Language so you can test from the Gramps program the links work?
Perhaps @sam888 (@gramps-project ) feels the same way for expanding the wiki’s translation status pages?
Is the feature request still the best way to initiate support for a Language? Or does that need to be follow with a message elsewhere? (The developer maillist perhaps? Or is there another forum in Weblate for Translators?)