Question: when was the last forced sterilization united states
[{'answer': '1981', 'provenance': [{'wikipedia_id': '720902', 'title': 'Compulsory sterilization', 'start_paragraph_id': 20, 'start_character': 927, 'end_paragraph_id': 20, 'end_character': 931, 'bleu_score': 1.0, 'section': 'Section::::By country.:Bangladesh.\n'}]}]