free spirit vs illegal alien

free spirit

noun
  • One who is a nonconformist or who does not recognize the authority of others. 

  • A member of the organized heretic movement Brethren of the Free Spirit in opposition of the Catholic Church from the 13th to 15th centuries. 

illegal alien

noun
  • A person who is within the boundaries of a political state without the authorization of the government of that state; a national of another country who has entered or stayed without permission. 

How often have the words free spirit and illegal alien occurred in a corpus of books? (source: Google Ngram Viewer )