Question: when was the diwani of bengal appointed to east india company
[{'answer': '12 August 1765', 'provenance': [{'wikipedia_id': '6265679', 'title': 'Treaty of Allahabad', 'start_paragraph_id': 1, 'start_character': 38, 'end_paragraph_id': 1, 'end_character': 52, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6265679', 'title': 'Treaty of Allahabad', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 1138, 'bleu_score': 0.786335276519836, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2829897213571592215}, 'section': 'Section::::Abstract.'}]}]