Question: when was gold discovered in the black hills
[{'answer': '1874', 'provenance': [{'wikipedia_id': '7244144', 'title': 'Black Hills Gold Rush', 'start_paragraph_id': 1, 'start_character': 91, 'end_paragraph_id': 1, 'end_character': 95, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '7244144', 'title': 'Black Hills Gold Rush', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 157, 'bleu_score': 0.9321022168949711, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16599951110734847192}, 'section': 'Section::::Abstract.'}]}]