henchman vs staffer

henchman

noun
  • An assistant member of a criminal gang. 

  • A loyal and trusted follower or subordinate. 

  • A person who supports a political figure chiefly out of selfish interests. 

staffer

noun
  • A member of a staff. 

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