Question: when did the currency of namibia first come into circulation
[{'answer': '1993', 'provenance': [{'wikipedia_id': '342430', 'title': 'Namibian dollar', 'start_paragraph_id': 1, 'start_character': 83, 'end_paragraph_id': 1, 'end_character': 87, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '342430', 'title': 'Namibian dollar', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 249, 'bleu_score': 0.869616082039926, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7071349027758366263}, 'section': 'Section::::Abstract.'}]}]