When an open, unanswered question has vote -1 it gets deleted after 30 days (
RemoveDeadQuestions). When it has a vote of 0 it gets removed after one year (
RemoveAbandonedQuestions). See this post on Meta SE.
These directives deleted 25 questions on 2018-11-24 and another 10 on 2018-12-01. Users with access to moderator tools can check this through the moderator tools.
I have acccess to moderator tools on 6 other sites. Under these directives, Earth Science had two and Space Exploration had one deleted between the two dates, versus 35 on Expats. Politics and Outdoors had none. Travel and Academia are much busier sites and too many posts have been manually deleted since those dates to count the number under these directives. Considering we have about 3.5 questions/day, or 49 per fortnight, assuming a constant rate, that means 71% of questions are automatically deleted. That can't possibly be healthy, and also means that our answer rate is in reality much worse than the 84% that is being reported.
I have only gained enough reputation to see deleted questions in the first place, so it may be that we live in exceptional times. Are we seeing unusual numbers of RemovedDeadQuestions and AbandonedQuestions right now, or is it normal for Expats that more than 2/3rd of questions are automatically deleted?