Question: when were the north west mounted police established
[{'answer': 'May 23 , 1873', 'provenance': [{'wikipedia_id': '584547', 'title': 'North-West Mounted Police', 'start_paragraph_id': 13, 'start_character': 58, 'end_paragraph_id': 13, 'end_character': 71, 'bleu_score': 1.0, 'section': 'Section::::History.:Establishment (1873–1874).:Formation.\n'}]}, {'provenance': [{'wikipedia_id': '584547', 'title': 'North-West Mounted Police', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 937, 'bleu_score': 0.986969988197764, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15695542021414558647}, 'section': 'Section::::History.:Establishment (1873–1874).:Formation.\n'}]}]