Question: how long has there been triple crown races
[{'answer': '1875', 'provenance': [{'wikipedia_id': '19116721', 'title': 'Triple Crown of Thoroughbred Racing (United States)', 'start_paragraph_id': 1, 'start_character': 314, 'end_paragraph_id': 1, 'end_character': 318, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '19116721', 'title': 'Triple Crown of Thoroughbred Racing (United States)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 535, 'bleu_score': 0.978606533029418, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9988030019391060251}, 'section': 'Section::::Abstract.'}]}]