What are minimum levels for each Affix Tier?

General
1

I assume that each Affix Tier has a minimum mob level for it to be considered among possibles affixes on an item. Is there a table of this somewhere? My understanding is that, once a rarity and affixes are chosen, each affix rolls a Tier among all possible Tiers (with equal probability? or biased towards lower Tiers?); what determines which Tiers are possible, other than the fact that T6 and T7 require rarity to be Exalted?

More generally, is there an article detailing item generation in this game?

2

You can search here for the level requirement of particular shards.

3

Thanks for your answer! I’ve looked there before, but unfortunately this only shows level requirement of shards/affixes, not their Tiers. What I’d like to know is, what determines the possible affix Tiers once an affix is selected?