Question: when did k9 first appear in doctor who
[{'answer': '1977', 'provenance': [{'wikipedia_id': '1228626', 'title': 'K9 (Doctor Who)', 'start_paragraph_id': 1, 'start_character': 236, 'end_paragraph_id': 1, 'end_character': 240, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1228626', 'title': 'K9 (Doctor Who)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1199, 'bleu_score': 0.923016871057701, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13726133593589091812}, 'section': 'Section::::Abstract.'}]}]