nigga vs shitskin

nigga

noun
  • A black person (usually male), especially an African American. 

  • A male as opposed to a female. 

  • A close and loyal friend. 

  • Any person, though chiefly male. 

shitskin

noun
  • A person with dark-coloured skin. 

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