Question: how long has ski halfpipe been an olympic event
[{'answer': '2014', 'provenance': [{'wikipedia_id': '37542428', 'title': 'Half-pipe skiing', 'start_paragraph_id': 1, 'start_character': 453, 'end_paragraph_id': 1, 'end_character': 457, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '37542428', 'title': 'Half-pipe skiing', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 616, 'bleu_score': 0.918993486882923, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15759358204146233865}, 'section': 'Section::::Abstract.'}]}]