Question: when did jehovah's witnesses get their name
[{'answer': '1931', 'provenance': [{'wikipedia_id': '52547', 'title': "Jehovah's Witnesses", 'start_paragraph_id': 2, 'start_character': 517, 'end_paragraph_id': 2, 'end_character': 521, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '52547', 'title': "Jehovah's Witnesses", 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 635, 'bleu_score': 0.9545695715275291, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10447697501170040290}, 'section': 'Section::::Abstract.'}]}]