Question: when did the samsung galaxy s8 plus come out
[{'answer': 'on 21 April 2017', 'provenance': [{'wikipedia_id': '53335244', 'title': 'Samsung Galaxy S8', 'start_paragraph_id': 1, 'start_character': 355, 'end_paragraph_id': 1, 'end_character': 371, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '53335244', 'title': 'Samsung Galaxy S8', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 519, 'bleu_score': 0.7811821867805571, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1438053614620539727}, 'section': 'Section::::Abstract.'}]}]