Question: when does season 8 for blue bloods start
[{'answer': 'September 29 , 2017', 'provenance': [{'wikipedia_id': '55391826', 'title': 'Blue Bloods (season 8)', 'start_paragraph_id': 1, 'start_character': 134, 'end_paragraph_id': 1, 'end_character': 153, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '55391826', 'title': 'Blue Bloods (season 8)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 186, 'bleu_score': 0.7819437868913751, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 719226283385649889}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '55391826', 'title': 'Blue Bloods (season 8)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The eighth season of "Blue Bloods", a police procedural drama series created by Robin Green and Mitchell Burgess, premiered on CBS on September 29, 2017. The season contained 22 episodes and concluded on May 11, 2018.', 'The eighth season of "Blue Bloods", a police procedural drama series created by Robin Green and Mitchell Burgess, premiered on CBS on September 29, 2017. The season contained 22 episodes and concluded on May 11, 2018.', 'The eighth season of "Blue Bloods", a police procedural drama series created by Robin Green and Mitchell Burgess, premiered on CBS on September 29, 2017.']}}]}]