Question: when did percy jackson sea of monsters come out
[{'answer': 'August 7 , 2013', 'provenance': [{'wikipedia_id': '36699915', 'title': 'Percy Jackson: Sea of Monsters', 'start_paragraph_id': 43, 'start_character': 837, 'end_paragraph_id': 43, 'end_character': 852, 'bleu_score': 1.0, 'section': 'Section::::Production.:Development.\n'}]}]