Question: the nigerian flag was design in what year
[{'answer': '1959', 'provenance': [{'wikipedia_id': '459277', 'title': 'Flag of Nigeria', 'start_paragraph_id': 1, 'start_character': 36, 'end_paragraph_id': 1, 'end_character': 40, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]