Question: when did delhi become capital of british india
[{'answer': 'December 12 , 1911'}, {'provenance': [{'wikipedia_id': '171705', 'title': 'List of capitals of India', 'start_paragraph_id': 21, 'start_character': 0, 'end_paragraph_id': 21, 'end_character': 242, 'bleu_score': 0.8671734184243891, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15451504957015048718}, 'section': 'Section::::Modern period.\n'}]}]