Question: when did brown v board of education take place
[{'answer': '1954', 'provenance': [{'wikipedia_id': '66402', 'title': 'Brown v. Board of Education', 'start_paragraph_id': 1, 'start_character': 53, 'end_paragraph_id': 1, 'end_character': 57, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]