In PUBG, each circle deals damage in a constant tickrate. The damage dealt increases with each circle while the tickrate seems constant. At the time of writing this question, damage dealt is constant no matter the distance to the next circle, which was changed in a later update. Assuming the player is not boosted, how much damage in HP% does each circle deal per tick?
This information would be helpful to assess, at what HP% you would have to take meds (Med Kit, First Aid Kit, ...) to avoid dying to the zone.