Question: when did justin bieber perform at madison square garden
[{'answer': 'August 31 , 2010', 'provenance': [{'wikipedia_id': '26336317', 'title': 'My World Tour', 'start_paragraph_id': 23, 'start_character': 178, 'end_paragraph_id': 23, 'end_character': 197, 'bleu_score': 1.0, 'section': 'Section::::Recordings and broadcasting.\n'}]}]