Question: when was the name changed from madras to chennai
[{'answer': '1996', 'provenance': [{'wikipedia_id': '45139', 'title': 'Chennai', 'start_paragraph_id': 1, 'start_character': 61, 'end_paragraph_id': 1, 'end_character': 65, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '45139', 'title': 'Chennai', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 415, 'bleu_score': 0.9699161750394991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 733504439136383103}, 'section': 'Section::::Etymology.\n'}]}]