Question: when did papua new guinea become an independent country
[{'answer': '16 September 1975', 'provenance': [{'wikipedia_id': '23401', 'title': 'History of Papua New Guinea', 'start_paragraph_id': 37, 'start_character': 263, 'end_paragraph_id': 37, 'end_character': 280, 'bleu_score': 1.0, 'section': 'Section::::Independence.\n'}]}, {'provenance': [{'wikipedia_id': '23401', 'title': 'History of Papua New Guinea', 'start_paragraph_id': 37, 'start_character': 0, 'end_paragraph_id': 37, 'end_character': 1214, 'bleu_score': 0.990171692033262, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16497187240380723631}, 'section': 'Section::::Independence.\n'}]}]