Question: who does peter griffin voice on family guy
[{'answer': 'Seth MacFarlane', 'provenance': [{'wikipedia_id': '6101072', 'title': 'List of Family Guy cast members', 'start_paragraph_id': 1, 'start_character': 185, 'end_paragraph_id': 1, 'end_character': 200, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6101072', 'title': 'List of Family Guy cast members', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 616, 'bleu_score': 0.9038203450479031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7265847586546516117}, 'section': 'Section::::Current cast.:Seth MacFarlane.\n'}]}]