Question: when did town lake became lady bird lake
[{'answer': 'July 26 , 2007', 'provenance': [{'wikipedia_id': '165936', 'title': 'Lady Bird Lake', 'start_paragraph_id': 6, 'start_character': 3, 'end_paragraph_id': 6, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '165936', 'title': 'Lady Bird Lake', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 478, 'bleu_score': 0.9757530668325981, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15802667186811434960}, 'section': 'Section::::History.\n'}]}]