Question: when did the us dollar leave the gold standard
[{'answer': '1934', 'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 58, 'start_character': 51, 'end_paragraph_id': 58, 'end_character': 55, 'bleu_score': 1.0, 'section': 'Section::::Abandonment of the gold standard.:Depression and World War II.:Great Depression.\n'}]}, {'answer': 'October 1976', 'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 66, 'start_character': 771, 'end_paragraph_id': 66, 'end_character': 783, 'bleu_score': 1.0, 'section': 'Section::::Abandonment of the gold standard.:Bretton Woods.\n'}]}, {'answer': 'August 15 , 1971', 'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 65, 'start_character': 446, 'end_paragraph_id': 65, 'end_character': 463, 'bleu_score': 1.0, 'section': 'Section::::Abandonment of the gold standard.:Bretton Woods.\n'}]}, {'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 58, 'start_character': 0, 'end_paragraph_id': 58, 'end_character': 521, 'bleu_score': 0.977897140678983, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3561880656383425890}, 'section': 'Section::::Abandonment of the gold standard.:Depression and World War II.:Great Depression.\n'}]}, {'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 66, 'start_character': 0, 'end_paragraph_id': 66, 'end_character': 974, 'bleu_score': 0.9870543337942441, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3561880656383425890}, 'section': 'Section::::Abandonment of the gold standard.:Bretton Woods.\n'}]}, {'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3561880656383425890}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'start_paragraph_id': 65, 'start_character': 0, 'end_paragraph_id': 65, 'end_character': 479, 'bleu_score': 0.9257921357402691, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3561880656383425890}, 'section': 'Section::::Abandonment of the gold standard.:Bretton Woods.\n'}]}, {'provenance': [{'wikipedia_id': '37412', 'title': 'Gold standard', 'section': 'Section::::Abandonment of the gold standard.:Bretton Woods.\n', 'start_paragraph_id': 65, 'end_paragraph_id': 65, 'meta': {'evidence_span': ['led U.S. President Richard Nixon to end international convertibility of the U.S. dollar to gold on August 15, 1971', 'the Vietnam War and persistent balance of payments deficits, led U.S. President Richard Nixon to end international convertibility of the U.S. dollar to gold on August 15, 1971 (the "Nixon Shock")', 'Starting in the 19591969 administration of President Charles de Gaulle and continuing until 1970, France reduced its dollar reserves, exchanging them for gold at the official exchange rate, reducing US economic influence. This, along with the fiscal strain of federal expenditures for the Vietnam War and persistent balance of payments deficits, led U.S. President Richard Nixon to end international convertibility of the U.S. dollar to gold on August 15, 1971 (the "Nixon Shock").']}}]}]