Not sure whats going on with the 40000ish with chance 0, too lazy to look deeply into it, but there are some 5000ish hits with chance != 0.. Lets up these..
Code:
UPDATE lootdrop_entries ld
INNER JOIN items i ON i.id=ld.item_id
INNER JOIN loottable_entries lt ON ld.lootdrop_id=lt.lootdrop_id
SET ld.chance = ld.chance * 4
WHERE i.Name like '%defiant%' and ld.chance > 0 and ld.chance < 25;
That would increase the currently dropping Defiant gear by 4.
Hmm, wonder whats up with all those chance 0's?