Question: when was star wars the empire strikes back released
[{'answer': '1980', 'provenance': [{'wikipedia_id': '53964', 'title': 'The Empire Strikes Back', 'start_paragraph_id': 1, 'start_character': 92, 'end_paragraph_id': 1, 'end_character': 96, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '53964', 'title': 'The Empire Strikes Back', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 538, 'bleu_score': 0.977139080690077, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1440586017587048423}, 'section': 'Section::::Abstract.'}]}]