Question: when did roe versus wade come into effect
[{'answer': '1973', 'provenance': [{'wikipedia_id': '68493', 'title': 'Roe v. Wade', 'start_paragraph_id': 1, 'start_character': 27, 'end_paragraph_id': 1, 'end_character': 31, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]