nig-nog vs nigga

nig-nog

noun
  • A person of color, especially, a black person. 

  • A foolish person; hence, a raw and unskilled recruit. 

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. 

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