How do enemy health, armour and shields scale with level?
Look at that, I think you gonna find what you're looking for : Enemy Level Scaling Warframe
In this article, you can find a lot of graphs that show you how enemy stats scale (health, health+armor...), how your affinity scale, and also the hitpoints and their effectiveness on enemies. Graphs are a bit tough to understand, but the text helps you a lot.
Hope it helps.