Question: when did subaru outback switch to timing chain
[{'answer': 'September 2010', 'provenance': [{'wikipedia_id': '13469732', 'title': 'List of Subaru engines', 'start_paragraph_id': 168, 'start_character': 215, 'end_paragraph_id': 168, 'end_character': 229, 'bleu_score': 1.0, 'section': 'Section::::Four Cylinder.:Subaru FB engine.\n'}]}, {'provenance': [{'wikipedia_id': '13469732', 'title': 'List of Subaru engines', 'start_paragraph_id': 168, 'start_character': 115, 'end_paragraph_id': 168, 'end_character': 427, 'bleu_score': 0.7544583329184381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14246387511066778525}, 'section': 'Section::::Four Cylinder.:Subaru FB engine.\n'}]}]