The Vanguard Belt

These are the properties that the item has so far:

Vanguard Belt (A new belt base type)
+305 to Armour and Evasion Rating
--------------------------
1% increased attack damage per 400 Armour and Evasion
15% chance to gain Fortify on Melee Stun
You have Onslaught while you have Fortify

if i had a char with 1200 evasion and 400 armour, would this belt grant....

1% attack ( because of only 400 armour AND evasion)

or

4% attack ( because of 1600 armour PLUS evasion)?