Question: who is the vice chairman of niti aayog constituted in 2015
[{'answer': 'Rajiv Kumar', 'provenance': [{'wikipedia_id': '44986807', 'title': 'NITI Aayog', 'start_paragraph_id': 34, 'start_character': 30, 'end_paragraph_id': 34, 'end_character': 41, 'bleu_score': 1.0, 'section': 'Section::::Members.\n'}]}]