This is the description of this 3rd level druid spell: 

Enemies in the area of effect have their skin infested by hordes of burrowing maggots, inflicting Raw damage over time. The more wounded the target, the greater the damage. A target at maximum Endurance takes no damage from the spell.

This spell inflicts 10.0 damage by percentage of Endurance lost. 

What this means? 

Tks, in advance, for your help my friends. Ask me anything if you need. 

 

The description is misleading. Not every point of percent counts. Afaik it's only the different stages of endurance ( below 75%, below 50%, near death: below 25%) that matter in this case. I don't know the exact formula though. 

But generally it's correct: the less endurance the target has the more damage it will get per tick from Maggots.