Question: how many digits in an employer federal identification number
[{'answer': 'nine', 'provenance': [{'wikipedia_id': '1608868', 'title': 'Employer Identification Number', 'start_paragraph_id': 1, 'start_character': 160, 'end_paragraph_id': 1, 'end_character': 164, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1608868', 'title': 'Employer Identification Number', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 738, 'bleu_score': 0.9832621206481431, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6840833440127604062}, 'section': 'Section::::Abstract.'}]}]