text: Actually, the URL I posted includes changeset info unrelated to that area.  Strip that away if you get confused, or instead fly the friendly skies over to
  https://www.openstreetmap.org/#map=18/21.54218/-77.26037&layers=N
  and marvel.  Zoom in and of course, zoom out then scroll all about.
  That explains the spike two months ago on Pascal's graph.  What I can't explain is the spike of some 5000 new notes in one month in South Korea, I believe, giving it a high number of unresolved notes overall but only a trickle of new ones per week nowadays.