Neither this month nor the past seven months have had an unusual number of questions closed. The last anomaly was in February when we had 41 questions closed. For reference, this month 19 questions have been closed. The February anomaly coincided with the Starman launch. We received a large number of questions during that time, many of which needed to be closed.
One thing that has been different about this year from 2016 and 2017 is that we haven't had an idle period. In 2016 and 2017 there were months where the number of questions closed dipped down to 9 (or even zero in January). This was due to having a lower volume of questions in general. This year we have not experienced a reduction in questions asked to the degree that we have seen such a dip in questions closed, not even in January. This is probably largely the aftermath of the Starman launch. While not everyone who asked questions during that time stuck around, we did get a number of new users.
That doesn't explain January, but perhaps we saw a surge of questions (relative to previous Januarys) at that time in preparation for the Starman launch.