Question: when was the salt tax imposed by the british government
[{'answer': '1759', 'provenance': [{'wikipedia_id': '16302106', 'title': 'History of the British salt tax in India', 'start_paragraph_id': 17, 'start_character': 3, 'end_paragraph_id': 17, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::Taxation of salt in India.:Taxation of salt by the British East India Company.\n'}]}, {'provenance': [{'wikipedia_id': '16302106', 'title': 'History of the British salt tax in India', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 292, 'bleu_score': 0.959574895300321, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 74629719265210270}, 'section': 'Section::::Taxation of salt in India.:Taxation of salt by the British East India Company.\n'}]}]