Question: when did the dollar become the reserve currency
[{'answer': '1944', 'provenance': [{'wikipedia_id': '177666', 'title': 'Reserve currency', 'start_paragraph_id': 14, 'start_character': 615, 'end_paragraph_id': 14, 'end_character': 619, 'bleu_score': 1.0, 'section': 'Section::::Theory.\n'}]}, {'provenance': [{'wikipedia_id': '177666', 'title': 'Reserve currency', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 751, 'bleu_score': 0.9844346099707091, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 178673230226051111}, 'section': 'Section::::Theory.\n'}]}]