Question: when was the last time undertaker was on wwe
[{'answer': 'WrestleMania 33', 'provenance': [{'wikipedia_id': '345792', 'title': 'The Undertaker', 'start_paragraph_id': 77, 'start_character': 619, 'end_paragraph_id': 77, 'end_character': 634, 'bleu_score': 1.0, 'section': 'Section::::Professional wrestling career.:World Wrestling Federation/Entertainment/WWE.:Sporadic appearances (2015–present).\n'}]}]