Question: when did jackie robinson retire from the mlb
[{'answer': '1956', 'provenance': [{'wikipedia_id': '16193', 'title': 'Jackie Robinson', 'start_paragraph_id': 68, 'start_character': 3, 'end_paragraph_id': 68, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::Playing career.:Major leagues.:1954 season, 1955 World Championship, and 1957 retirement.\n'}]}, {'provenance': [{'wikipedia_id': '16193', 'title': 'Jackie Robinson', 'start_paragraph_id': 68, 'start_character': 0, 'end_paragraph_id': 68, 'end_character': 857, 'bleu_score': 0.925025467416217, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1976822703109460564}, 'section': 'Section::::Playing career.:Major leagues.:1954 season, 1955 World Championship, and 1957 retirement.\n'}]}]