Up to 4. Every item page has the same field in its sidebar.

Stat	Azus+3 D11ChineseSeal of Nova × Change Seal of Nova Seal of Nova · RARE Plus0123456789101112
Melee Attack Power	1,573~1,755
Magical Attack Power	2,679~3,043
Melee Specialization(%)	223.3~251.7
Magical Specialization(%)	380~436.8
Accuracy	117
Critical	3
Durability	124

Orange is the higher stat, ranked by the middle of the pair ((min + max) / 2): 23~28 against 20~34 has no answer without a rule. The faint number is how far that column sits behind. Values are what the item has empty. A dash means the item has no such stat at all — not that it has zero.

Nothing here is ranked: a lower required level is an advantage to one player and a different item to another.