Question: when did just dance by lady gaga come out
[{'answer': 'April 8 , 2008', 'provenance': [{'wikipedia_id': '18097249', 'title': 'Just Dance (song)', 'start_paragraph_id': 1, 'start_character': 183, 'end_paragraph_id': 1, 'end_character': 199, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18097249', 'title': 'Just Dance (song)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 418, 'bleu_score': 0.9408228243926111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8138973288945713978}, 'section': 'Section::::Abstract.'}]}]