'Twelve' in the Bible

And Jehoram son of Ahab hath reigned over Israel, in Samaria, in the eighteenth year of Jehoshaphat king of Judah, and he reigneth twelve years,

A son of twelve years is Manasseh in his reigning, and fifty and five years he hath reigned in Jerusalem, and the name of his mother is Hephzi-Bah;