Question: when did back that thang up come out
[{'answer': 'February 24 , 1999', 'provenance': [{'wikipedia_id': '2924733', 'title': 'Back That Thang Up', 'start_paragraph_id': 1, 'start_character': 236, 'end_paragraph_id': 1, 'end_character': 256, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2924733', 'title': 'Back That Thang Up', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 444, 'bleu_score': 0.695625657913558, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9278444182597324067}, 'section': 'Section::::Abstract.'}]}]