Question: when did canada change from pounds to dollars
[{'answer': 'the mid-19th century', 'provenance': [{'wikipedia_id': '4303206', 'title': 'History of the Canadian dollar', 'start_paragraph_id': 44, 'start_character': 7, 'end_paragraph_id': 44, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::From the British pound to the Canadian dollar: 1825–1867.\n'}]}, {'provenance': [{'wikipedia_id': '4303206', 'title': 'History of the Canadian dollar', 'start_paragraph_id': 44, 'start_character': 0, 'end_paragraph_id': 44, 'end_character': 486, 'bleu_score': 0.9738505480425671, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18283265828584303962}, 'section': 'Section::::From the British pound to the Canadian dollar: 1825–1867.\n'}]}]