Question: when did the current australian flag became official
[{'answer': '23 February 1908'}, {'provenance': [{'wikipedia_id': '5094710', 'title': 'Flag of Australia', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 586, 'bleu_score': 0.9427836745142131, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15679952121308356101}, 'section': 'Section::::Abstract.'}]}]