Question: when did the united farm workers union start
[{'answer': 'August 1966', 'provenance': [{'wikipedia_id': '294510', 'title': 'United Farm Workers', 'start_paragraph_id': 12, 'start_character': 994, 'end_paragraph_id': 12, 'end_character': 1005, 'bleu_score': 1.0, 'section': 'Section::::History.:Founding of the UFW.\n'}]}, {'provenance': [{'wikipedia_id': '294510', 'title': 'United Farm Workers', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 1005, 'bleu_score': 0.9668954950326201, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10492121634930435062}, 'section': 'Section::::History.:Founding of the UFW.\n'}]}]