Question: when was the tiger who came to tea first published
[{'answer': '1968', 'provenance': [{'wikipedia_id': '9173395', 'title': 'The Tiger Who Came to Tea', 'start_paragraph_id': 1, 'start_character': 91, 'end_paragraph_id': 1, 'end_character': 95, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '9173395', 'title': 'The Tiger Who Came to Tea', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 401, 'bleu_score': 0.9452425713908251, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10688334264180632184}, 'section': 'Section::::Abstract.'}]}]