Increasing Maximum Life by a Percent?

What I need is a way to upgrade units' maximum life by a %, and have that % change every lvl (lvl 1 is 50%, lvl 2 is 45%, lvl 3 is 30%, etc). I know upgrades allow upgrading by %, but the amount of % is static throughout the upgrade. I looked in triggers and couldn't find a way to set unit maximum hp (I SWEAR there was one, but I can't find it.)

The only availible options I see right now are:
1. Have 100 seperate upgrades, each giving a different % (I think there are a ton of problems with this, most of them imagined though.)
2. Have every unit have max hp, and set current hp with triggers, and don't allow any of the units to have hp regen. (reminiscient of how HP upgrades are done in starcraft, if any of you are familiar with SCUMS.)
3. Go insane over trying to figure this stupid problem.
EDIT: 4. Please don't even suggest creating secondary units. It's not even funny how impossible that would be.

If anyone can help me out with a cleaner way of doing this, I'll give them IMAGINARY rep and my eternal gratitude! I'm getting desperate here. HELP PLEASE!

So, it's just a regular unit upgrade, right? And the problem is that each time you upgrade it, it increases by a different percentage?

With your example there, I'm not quite sure, but I'm guessing you want it to act as one multiple-leveled upgrade like this:

not upgraded - 100hp (just for example)
1st - 150hp
2nd - 150%+45% = 195hp
3rd - 195%+30% = 223hp

If it's like that, I'm not quite sure how to do it easily. Unless there's a "defealt max life of unit-type" real variable, triggering max life increases might not be that bad (but you might need WEU with some advanced spells or something?).

But if it's a recursive multiplication of the hp (((100hp*150%)*145%)*130%), then:
Instead of using "100" different upgrades, just use as many upgrades as you need (one for each time you upgrade it). Have a main upgrade that does nothing, it's just there for the player to click. Whenever you upgrade it, the triggers 'research' a hidden upgrade that actually gives an hp increase (the first upgrade increases hp by 50%, the second by 45%, etc.)

Yay, fake rep!

What you want is Weaaddar or Vex's BounusMod. It allows a trigger to increase max HP/MP of a unit. (That option is not in the normal WE.) Check Lord Vexorian's subdomain for it.

Coukld anyone post a link to the bonusmod, I've looked and am not getting any luck/

InvX. Look up InvX at Lord Vexorian's Subdomain.