Question: what was the first year for the morgan silver dollar
[{'answer': '1878', 'provenance': [{'wikipedia_id': '2068555', 'title': 'Morgan dollar', 'start_paragraph_id': 1, 'start_character': 62, 'end_paragraph_id': 1, 'end_character': 66, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2068555', 'title': 'Morgan dollar', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 522, 'bleu_score': 0.977139080690077, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6103844656450196733}, 'section': 'Section::::Abstract.'}]}]