idiot savant vs prodigy

idiot savant

noun
  • A person who exhibits an extraordinary ability in one subject (often mathematics) whilst being intellectually disabled in many other domains. 

prodigy

noun
  • An extremely talented person, especially a child. 

  • A wonderful example of something. 

  • An extraordinary occurrence or creature; an anomaly, especially a monster; a freak. 

  • An amazing or marvellous thing; a wonder. 

How often have the words idiot savant and prodigy occurred in a corpus of books? (source: Google Ngram Viewer )