Question: when was the first dyson vacuum cleaner invented
[{'answer': '1979', 'provenance': [{'wikipedia_id': '1576612', 'title': 'Dyson (company)', 'start_paragraph_id': 5, 'start_character': 367, 'end_paragraph_id': 5, 'end_character': 371, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '1576612', 'title': 'Dyson (company)', 'start_paragraph_id': 5, 'start_character': 319, 'end_paragraph_id': 5, 'end_character': 714, 'bleu_score': 0.895039260309043, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10770264982220405281}, 'section': 'Section::::History.\n'}]}]