Question: when did the red guards start and end
[{'answer': '1966 and 1967', 'provenance': [{'wikipedia_id': '1169199', 'title': 'Red Guards', 'start_paragraph_id': 1, 'start_character': 105, 'end_paragraph_id': 1, 'end_character': 118, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'in 1966 and 1967', 'provenance': [{'wikipedia_id': '1169199', 'title': 'Red Guards', 'start_paragraph_id': 1, 'start_character': 102, 'end_paragraph_id': 1, 'end_character': 118, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1169199', 'title': 'Red Guards', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5524235191460478347}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1169199', 'title': 'Red Guards', 'section': 'Section::::Role in the Cultural Revolution.\n', 'start_paragraph_id': 11, 'end_paragraph_id': 11, 'meta': {'evidence_span': ['A high school Red Guard put a red arm band inscribed with the characters for "Red Guard" on the Chairman, who stood for six hours. The 8-18 rally, as it was known, was the first of eight receptions the Chairman gave to Red Guards in Tienanmen in the fall of 1966.', 'The rally was led by Chen Boda, and Lin Biao gave a keynote speech. Red Guard leaders led by Nie Yuanzi also gave speeches. A high school Red Guard put a red arm band inscribed with the characters for "Red Guard" on the Chairman, who stood for six hours. The 8-18 rally, as it was known, was the first of eight receptions the Chairman gave to Red Guards in Tienanmen in the fall of 1966. It was this rally that signified the beginning of the Red Guards\' involvement in implementing the aims of the Cultural Revolution. A second rally, held on 31 August, was led by Kang Sheng and Lin Biao also donned a red arm band. The last rally was held on 26 November 1966. In all, the Chairman greeted eleven to twelve', "man, who stood for six hours. The 8-18 rally, as it was known, was the first of eight receptions the Chairman gave to Red Guards in Tienanmen in the fall of 1966. It was this rally that signified the beginning of the Red Guards' involvement in implementin"]}}]}, {'provenance': [{'wikipedia_id': '1169199', 'title': 'Red Guards', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['Red Guards () were a mass student-led paramilitary social movement mobilized and guided by Mao Zedong in 1966 and 1967, during the first phase of the Chinese Cultural Revolution, which he had instituted.', 'Red Guards () were a mass student-led paramilitary social movement mobilized and guided by Mao Zedong in 1966 and 1967, during the first phase of the Chinese Cultural Revolution, which he had instituted.']}}]}]