pongo vs warfighter

pongo

noun
  • A soldier. 

  • A lazy, good for nothing person. 

  • A canyon or gorge in South America especially cutting through a ridge or mountain range. 

warfighter

noun
  • A soldier (especially of the United States military). 

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