Question: when did the union jack become the union flag
[{'answer': '1801', 'provenance': [{'wikipedia_id': '70760', 'title': 'Union Jack', 'start_paragraph_id': 4, 'start_character': 121, 'end_paragraph_id': 4, 'end_character': 125, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '70760', 'title': 'Union Jack', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 386, 'bleu_score': 0.9348189981364851, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10485649426818036479}, 'section': 'Section::::Abstract.'}]}]