nig-nog vs wog

nig-nog

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

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

wog

noun
  • Any dark-skinned person: originally specifically an Indian, but later also anybody of North African, Mediterranean, or Middle Eastern ancestry. 

  • A bug, an insect. 

  • A person of Southern European, Mediterranean, Middle Eastern, or Southeastern European ancestry. 

  • A pollywog, or sailor who has never crossed the Equator. 

  • A minor illness caused by bacteria, virus, intestinal parasite, etc. 

  • A person who is not a Scientologist. 

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