Question: when did oando commence business operations as a petroleum marketing company
[{'answer': '1956', 'provenance': [{'wikipedia_id': '22082754', 'title': 'Oando', 'start_paragraph_id': 8, 'start_character': 72, 'end_paragraph_id': 8, 'end_character': 76, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]