Question: when did the stockton to darlington railway open
[{'answer': '1825', 'provenance': [{'wikipedia_id': '326299', 'title': 'Stockton and Darlington Railway', 'start_paragraph_id': 1, 'start_character': 106, 'end_paragraph_id': 1, 'end_character': 110, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '326299', 'title': 'Stockton and Darlington Railway', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 639, 'bleu_score': 0.9810405040225261, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7340651926517932686}, 'section': 'Section::::Abstract.'}]}]