Question: when did the yellow fever epidemic of 1793 start
[{'answer': 'spring of 1793', 'provenance': [{'wikipedia_id': '13909129', 'title': '1793 Philadelphia yellow fever epidemic', 'start_paragraph_id': 5, 'start_character': 7, 'end_paragraph_id': 5, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Beginnings.\n'}]}, {'provenance': [{'wikipedia_id': '13909129', 'title': '1793 Philadelphia yellow fever epidemic', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 748, 'bleu_score': 0.983804329702269, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14269389555529332072}, 'section': 'Section::::Beginnings.\n'}]}]