hooligan vs rioter

hooligan

noun
  • A person who causes trouble or violence. 

  • A type of fish, an anadromous smelt, Thaleichthys pacificus, found in the North Pacific. 

  • A member of the coast guard. 

rioter

noun
  • One who riots; part of the unruly violent crowd causing a riot. 

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