Question: when did the referendum occur and in what states
[{'answer': '27 May 1967', 'provenance': [{'wikipedia_id': '1239701', 'title': '1967 Australian referendum (Aboriginals)', 'start_paragraph_id': 1, 'start_character': 29, 'end_paragraph_id': 1, 'end_character': 40, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'six states', 'provenance': [{'wikipedia_id': '1239701', 'title': '1967 Australian referendum (Aboriginals)', 'start_paragraph_id': 1, 'start_character': 417, 'end_paragraph_id': 1, 'end_character': 427, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1239701', 'title': '1967 Australian referendum (Aboriginals)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 962, 'bleu_score': 0.933305858957382, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2140313313718368434}, 'section': 'Section::::Abstract.'}]}]