Question: when was the dollar coin introduced in australia
[{'answer': '14 May 1984', 'provenance': [{'wikipedia_id': '4622015', 'title': 'Australian one dollar coin', 'start_paragraph_id': 2, 'start_character': 23, 'end_paragraph_id': 2, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4622015', 'title': 'Australian one dollar coin', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 278, 'bleu_score': 0.910036530027129, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10493418958137043235}, 'section': 'Section::::Abstract.'}]}]