Guardian additional armor up

I am aware When you parry and heavy attack you gain an armor up buff in addition to the permanent one you have.
The question I have is , how much does each additional armor up add to the armor rating. Does it give 100% additional armor rating for each armor up buff
Example:
Original armor up = 2100
3 more equals = 6300
Grand total of
8400 armor rating
No where an anY description Does it specify
The question I have is , how much does each additional armor up add to the armor rating. Does it give 100% additional armor rating for each armor up buff
Example:
Original armor up = 2100
3 more equals = 6300
Grand total of
8400 armor rating
No where an anY description Does it specify
0