Question: when did the brown vs the board of education start
[{'answer': '1951', 'provenance': [{'wikipedia_id': '66402', 'title': 'Brown v. Board of Education', 'start_paragraph_id': 2, 'start_character': 146, 'end_paragraph_id': 2, 'end_character': 150, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '66402', 'title': 'Brown v. Board of Education', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 238, 'bleu_score': 0.9529077664391161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4195142233532988725}, 'section': 'Section::::Case.:Filing and arguments.\n'}]}]