Question: how many ethnic groups are there in cameroon
[{'answer': 'approximately 250', 'provenance': [{'wikipedia_id': '23352980', 'title': 'Ethnic groups in Cameroon', 'start_paragraph_id': 1, 'start_character': 66, 'end_paragraph_id': 1, 'end_character': 83, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '23352980', 'title': 'Ethnic groups in Cameroon', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 684, 'bleu_score': 0.8921033513531911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16768057973540397404}, 'section': 'Section::::Abstract.'}]}]