Question: when was the first international yoga day celebrated
[{'answer': '2015', 'provenance': [{'wikipedia_id': '44270128', 'title': 'International Day of Yoga', 'start_paragraph_id': 5, 'start_character': 3, 'end_paragraph_id': 5, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::Origin.\n'}]}, {'provenance': [{'wikipedia_id': '44270128', 'title': 'International Day of Yoga', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 474, 'bleu_score': 0.8334935842230191, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11269638756791039352}, 'section': 'Section::::Abstract.'}]}]