A319 Captain reported exceeding nose wheel steering trim limits to taxi the aircraft straight; resulting in a gate return and aircraft refusal.

Narrative

On taxi out in ZZZ; the nose wheel steering was pulling to the right excessively. We put in 6.6 units of left trim to taxi the plane straight on the taxiway with both engines running and a tailwind. The plane had a few write ups for the same thing; one being by us in ZZZ1-ZZZ which required 3 units of trim to taxi straight. I had discussed with Maintenance Control in ZZZ1 and said it was within the limits for the carry forward item. So now needing 6.6 units in ZZZ on the taxi out; it seems to be getting progressively worse. After consulting again with Dispatch; Maintenance Control; my First Officer (FO); and considering the forecasted winds at arrival time in ZZZ1 were suppose to be in excess of a 30 kt. crosswind; I determined the safest course of action was to return to gate considering all the possibilities. On the return taxi; with a headwind now the nose wheel steering required 8.4 units to maintain a straight taxi. I reported these findings to Maintenance Control as well; that in 3 taxis I had done in this plane it has gone from 3 to 6.6 now to 8.4 units of left trim just to keep the plane taxiing straight.