Question: when did google start working on driverless cars
[{'answer': '2009', 'provenance': [{'wikipedia_id': '29156200', 'title': 'Waymo', 'start_paragraph_id': 4, 'start_character': 69, 'end_paragraph_id': 4, 'end_character': 73, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]