Question: when did the siege of savannah take place
[{'answer': 'Savannah , Georgia', 'provenance': [{'wikipedia_id': '1131138', 'title': 'Siege of Savannah', 'start_paragraph_id': 4, 'start_character': 327, 'end_paragraph_id': 4, 'end_character': 348, 'bleu_score': 1.0, 'section': 'Section::::Background.\n'}]}, {'provenance': [{'wikipedia_id': '1131138', 'title': 'Siege of Savannah', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 751, 'bleu_score': 0.9634320912002211, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13577658991510630182}, 'section': 'Section::::Abstract.'}]}]