Question: when was 50 shades of grey book released
[{'answer': 'May 2011', 'provenance': [{'wikipedia_id': '35166850', 'title': 'Fifty Shades of Grey', 'start_paragraph_id': 11, 'start_character': 194, 'end_paragraph_id': 11, 'end_character': 202, 'bleu_score': 1.0, 'section': 'Section::::Background and publication.\n'}]}, {'provenance': [{'wikipedia_id': '35166850', 'title': 'Fifty Shades of Grey', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 1673, 'bleu_score': 0.9537844892017111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5505740950112626185}, 'section': 'Section::::Background and publication.\n'}]}]