Increasing a non hero units max hp

[TheLegend]

The title tells it all. How can I increase a non hero's max hp with jass or vjass. I already made a library holding each units stats and in it there is an integer called constitution. The formula is this
MAXHP = base_level_hp + constitution*25
I tried setting the hp to a % but it doesn't increase but heals the unit

 

[Narks]

look for a system called Status by Jesus4Lyf, under tutorials and resources

 

[WolfieeifloW]

Status.