The reason for the incosistent sales ex. WW 1 higher than the rebirth issue, is the print numbers. Retailers didn't expect Rebirth to do well, so they ordered small. But after the first wave selled like hot-cakes, they reordered (advance reorders), hence the later issues selling better. For example Ac 957 has gone through three prints. Two of them will count as July issues.
So the first months are gonna be very inconsistent. Until the titles find their audiences.