Question: how many american lives have been lost in the afghanistan war
[{'answer': '2,254'}, {'provenance': [{'wikipedia_id': '22081350', 'title': 'United States military casualties in the War in Afghanistan', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 189, 'bleu_score': 0.5920893212447781, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17502972691879963119}, 'section': 'Section::::Numbers of fatalities.\n'}]}]