Question: when did season 1 of this is us start
[{'answer': 'September 20 , 2016', 'provenance': [{'wikipedia_id': '52995450', 'title': 'This Is Us (season 1)', 'start_paragraph_id': 67, 'start_character': 26, 'end_paragraph_id': 67, 'end_character': 45, 'bleu_score': 1.0, 'section': 'Section::::Broadcast.\n'}]}, {'provenance': [{'wikipedia_id': '52995450', 'title': 'This Is Us (season 1)', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 648, 'bleu_score': 0.9813933169956551, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12380410263731236495}, 'section': 'Section::::Abstract.'}]}]