extraction vs skin color

extraction

noun
  • A person's origin or ancestry. 

  • A removal of a tooth from its socket. 

  • Something extracted, an extract, as from a plant or an organ of an animal etc. 

  • An act of extracting or the condition of being extracted. 

  • An act of removing someone from a hostile area to a secure location. 

skin color

noun
  • One's ethnicity. 

  • The color of human skin. 

How often have the words extraction and skin color occurred in a corpus of books? (source: Google Ngram Viewer )