BRONZE Stats(Category="GethPrime", CategoryData=((StatName="MaxHealth",StatRange=(X=5000.0f,Y=7500.0f)),(StatName="MaxShields",StatRange=(X=3500.0f,Y=5250.0f)),(StatName="ShieldDrone_MaxHealth",StatRange=(X=300.0f,Y=375.0f)),(StatName="Turret_MaxHealth",StatRange=(X=250.0f,Y=325.0f))
GOLD Stats(Category="GethPrime", CategoryData=((StatName="MaxHealth",StatRange=(X=11250.0f,Y=16875.0f)),(StatName="MaxShields",StatRange=(X=7875.0f,Y=11812.0f)),(StatName="ShieldDrone_MaxHealth",StatRange=(X=300.0f,Y=375.0f)),(StatName="Turret_MaxHealth",StatRange=(X=250.0f,Y=325.0f))
Every other stat is the same, for how much the shield drone heals and how often, how often drone and turret spawn, etc...
I am unsure for the difference between X stats and Y stats, my best guess is the Y stats is when it is "target" in the select missions to kill the 4 targets, because they are always harder to kill.
If want more information or on a specific monster leave a comment and I can update for that specific monster, but those numbers should be true for every monster. Which is about a 50% increase in health/shields per difficulty level.