Question: how many seasons of vikings have been made
[{'answer': '5', 'provenance': [{'wikipedia_id': '38824857', 'title': 'List of Vikings episodes', 'start_paragraph_id': 4, 'start_character': 37, 'end_paragraph_id': 4, 'end_character': 38, 'bleu_score': 1.0, 'section': 'Section::::Webisodes.\n'}]}]