'Eighteenth' in the Bible

In the eighteenth year of King Jeroboam, Abijah became king over Judah.

Now in the eighteenth year of his rule, when the land and the house had been made clean, he sent Shaphan, the son of Azaliah, and Maaseiah, the ruler of the town, and Joah, the son of Joahaz, the recorder, to make good what was damaged in the house of the Lord his God.

In the eighteenth year of the rule of Josiah this Passover was kept.