Question: when did harry potter and the deathly hallows book come out
[{'answer': '21 July 2007', 'provenance': [{'wikipedia_id': '776049', 'title': 'Harry Potter and the Deathly Hallows', 'start_paragraph_id': 1, 'start_character': 183, 'end_paragraph_id': 1, 'end_character': 195, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '776049', 'title': 'Harry Potter and the Deathly Hallows', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 615, 'bleu_score': 0.9258560918183311, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2659207062481885650}, 'section': 'Section::::Abstract.'}]}]