Question: when did madras changed its name to chennai
[{'answer': '1996', 'provenance': [{'wikipedia_id': '850010', 'title': 'Renaming of cities in India', 'start_paragraph_id': 6, 'start_character': 550, 'end_paragraph_id': 6, 'end_character': 554, 'bleu_score': 1.0, 'section': 'Section::::Renaming in local languages.\n'}]}]