Question: when was the terracotta army discovered in china
[{'answer': '29 March 1974', 'provenance': [{'wikipedia_id': '148653', 'title': 'Terracotta Army', 'start_paragraph_id': 6, 'start_character': 19, 'end_paragraph_id': 6, 'end_character': 32, 'bleu_score': 1.0, 'section': 'Section::::History.:Discovery.\n'}]}, {'provenance': [{'wikipedia_id': '148653', 'title': 'Terracotta Army', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 610, 'bleu_score': 0.7635026445637491, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17448684591354326718}, 'section': 'Section::::History.:Discovery.\n'}]}]