Question: when did they stop making the wheat penny
[{'answer': '1959', 'provenance': [{'wikipedia_id': '164092', 'title': 'Penny (United States coin)', 'start_paragraph_id': 1, 'start_character': 408, 'end_paragraph_id': 1, 'end_character': 412, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '164092', 'title': 'Penny (United States coin)', 'start_paragraph_id': 34, 'start_character': 0, 'end_paragraph_id': 34, 'end_character': 730, 'bleu_score': 0.983804329702269, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2305240080717092794}, 'section': 'Section::::Lincoln cent.\n'}]}]