Question: when was the prudential building in chicago built
[{'answer': '1955', 'provenance': [{'wikipedia_id': '4533889', 'title': 'One Prudential Plaza', 'start_paragraph_id': 1, 'start_character': 113, 'end_paragraph_id': 1, 'end_character': 117, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4533889', 'title': 'One Prudential Plaza', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 460, 'bleu_score': 0.858978122802852, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16989316164496447462}, 'section': 'Section::::Abstract.'}]}]