Task: Question Generation
Input (English): Passage: 1533-47: some 20 large raids on the frontiers.:71 1541: Crimean Khan crosses the Oka river on rafts under covering fire from Turkish guns.:12 1555,1562,1664,1565 The Khan lead a large army into Muscovy.:16.
Output (English): How many years passed by during the 20 large raids?