Question: when did the ibm selectric typewriter come out
[{'answer': '31 July 1961', 'provenance': [{'wikipedia_id': '23861711', 'title': 'IBM Selectric typewriter', 'start_paragraph_id': 1, 'start_character': 109, 'end_paragraph_id': 1, 'end_character': 121, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '23861711', 'title': 'IBM Selectric typewriter', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 121, 'bleu_score': 0.9021315316859231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13699037771066402433}, 'section': 'Section::::Abstract.'}]}]