ananym vs family name

ananym

noun
  • A pseudonym derived by spelling one's name backwards. 

family name

noun
  • A given name common in a family, or already borne by someone in the family (in the context of naming someone in the family after that family member). 

  • A surname. 

How often have the words ananym and family name occurred in a corpus of books? (source: Google Ngram Viewer )