Helaman 11:29

But behold, it came to pass that in that same year, they were driven back even into their own lands. And thus ended the eightieth year of the reign of the Judges over the people of Nephi.

But that same year, the army was pushed back to their own lands. That’s how the eightieth year ended.

But that same year, the army was driven all the way back to their own territory. That’s how the eightieth year ended.