Question: when was the subway system built in nyc
[{'answer': '1904', 'provenance': [{'wikipedia_id': '285510', 'title': 'New York City Subway', 'start_paragraph_id': 1, 'start_character': 224, 'end_paragraph_id': 1, 'end_character': 228, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '285510', 'title': 'New York City Subway', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 503, 'bleu_score': 0.978606533029418, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5426693555087182976}, 'section': 'Section::::Abstract.'}]}]