Question: when did the song unchained melody come out
[{'answer': '1955', 'provenance': [{'wikipedia_id': '359664', 'title': 'Unchained Melody', 'start_paragraph_id': 1, 'start_character': 24, 'end_paragraph_id': 1, 'end_character': 28, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '359664', 'title': 'Unchained Melody', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 532, 'bleu_score': 0.978375183951072, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13971105118338570429}, 'section': 'Section::::Abstract.'}]}]