Spirit's health

Well hello, I have 2 questions about ritualist spirits, in factions, first of all; each point of spawning power gives spirits 4% more max. health, but is that calculated over the base health (base health+(1.04*rank in spawning)), or over the previous rank of spawning (base health*1.04^(rank in spawning))

And my 2nd question; how is the base health (without ranks in spawning) calculated? Is it the same as a normal char (L7 spirit has the same health as a lvl 7 char) or what?

No-one got a clue?

This would be easily tested with something like Union, that takes a set easy to work with nmumber of health from itself when your hit.