Question: when was the first pc sold to the public
[{'answer': '1974', 'provenance': [{'wikipedia_id': '18457137', 'title': 'Personal computer', 'start_paragraph_id': 14, 'start_character': 90, 'end_paragraph_id': 14, 'end_character': 94, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '18457137', 'title': 'Personal computer', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 570, 'bleu_score': 0.9030952865719301, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9857052490063172914}, 'section': 'Section::::History.\n'}]}]