Answer:
As during the civil war, African elephants with tusks were targeted, and the tuskless elephants were left alone. This, in turn, allowed for the tuskless elephant populace to thrive and continuously grow, while the tusked elephants saw a decline as more and more were poached. So, it is only natural that as time progresses, and assuming the circumstances remain constant, that the tusked elephant population will see a negative trend, and inversely the tuskless elephant population will see a positive trend.