Question: when was ambala established as a cantonment area
[{'answer': '1843', 'provenance': [{'wikipedia_id': '5702763', 'title': 'Ambala Cantonment', 'start_paragraph_id': 1, 'start_character': 197, 'end_paragraph_id': 1, 'end_character': 201, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]