Question: when was birth control made legal in the us
[{'answer': 'March 22 , 1972', 'provenance': [{'wikipedia_id': '33463304', 'title': 'Birth control in the United States', 'start_paragraph_id': 17, 'start_character': 941, 'end_paragraph_id': 17, 'end_character': 956, 'bleu_score': 1.0, 'section': "Section::::History.:The sexual revolution and 'the pill'.\n"}]}, {'provenance': [{'wikipedia_id': '33463304', 'title': 'Birth control in the United States', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 1122, 'bleu_score': 0.9892179350238061, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7721283169745788397}, 'section': "Section::::History.:The sexual revolution and 'the pill'.\n"}]}]