Question: when's the last time washington capitals won stanley cup
[{'answer': '2018', 'provenance': [{'wikipedia_id': '73125', 'title': 'Washington Capitals', 'start_paragraph_id': 2, 'start_character': 631, 'end_paragraph_id': 2, 'end_character': 635, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '73125', 'title': 'Washington Capitals', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 647, 'bleu_score': 0.7927891032301231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14624391682548840657}, 'section': 'Section::::Abstract.'}]}]