Question: how many seasons of vampire diaries r there
[{'answer': '8', 'provenance': [{'wikipedia_id': '22823014', 'title': 'The Vampire Diaries', 'start_paragraph_id': 3, 'start_character': 270, 'end_paragraph_id': 3, 'end_character': 271, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'eight', 'provenance': [{'wikipedia_id': '22823014', 'title': 'The Vampire Diaries', 'start_paragraph_id': 1, 'start_character': 309, 'end_paragraph_id': 1, 'end_character': 314, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '22823014', 'title': 'The Vampire Diaries', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 322, 'bleu_score': 0.8858241416822491, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6720262692417940172}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '22823014', 'title': 'The Vampire Diaries', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 554, 'bleu_score': 0.9541060922758601, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6720262692417940172}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '22823014', 'title': 'The Vampire Diaries', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['eight seasons', 'The Vampire Diaries is an American supernatural teen drama television series developed by Kevin Williamson and Julie Plec, based on the popular book series of the same name written by L. J. Smith. The series premiered on The CW on September 10, 2009, and concluded on March 10, 2017, airing 171 episodes over eight seasons.\rhighlight sentence(s) containing evidence, not only the answer', 'The series premiered on The CW on September 10, 2009, and concluded on March 10, 2017, airing 171 episodes over eight seasons.']}}]}]