infiltrator vs squatter

infiltrator

noun
  • One who infiltrates an organization or territory; an undercover or covert agent. 

squatter

noun
  • A poor vagrant; An illegal informal settler; hobo; beggar; One suffering from extreme poverty. 

  • One who occupied Crown land. 

  • A large-scale grazier and landowner. 

  • One who squats, sits down idly. 

  • A squat toilet. 

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