[Sitting back down and toying with her fork! Not going to stuff her face yet, gotta look a bit more sober and answer the question after all.]

To my personal experience, 2 instances, but there has been at least two more prior to my own arrival, from what I could gather. [She's been here since end November and apparently came right after something big. Sat in the December and January disturbances, and heard about the one in October. Hm... Close enough?]