Question: when did the last episode of how i met your mother air
[{'answer': 'March 31 , 2014', 'provenance': [{'wikipedia_id': '37998428', 'title': 'How I Met Your Mother (season 9)', 'start_paragraph_id': 1, 'start_character': 191, 'end_paragraph_id': 1, 'end_character': 206, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '37998428', 'title': 'How I Met Your Mother (season 9)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 616, 'bleu_score': 0.981898582188057, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11575357707278126181}, 'section': 'Section::::Abstract.'}]}]