Question: when did the us end its open door policy
[{'answer': '1922', 'provenance': [{'wikipedia_id': '524043', 'title': 'Open Door Policy', 'start_paragraph_id': 13, 'start_character': 1192, 'end_paragraph_id': 13, 'end_character': 1196, 'bleu_score': 1.0, 'section': 'Section::::Open Door Policy in China.:Subsequent development.\n'}]}, {'provenance': [{'wikipedia_id': '524043', 'title': 'Open Door Policy', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 1239, 'bleu_score': 0.954525525479722, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7531898418519282503}, 'section': 'Section::::Open Door Policy in China.:Subsequent development.\n'}]}]