Remainer vs serenity

Remainer

noun
  • Someone who supports the United Kingdom remaining within the European Union. 

serenity

noun
  • A title given to a reigning prince or similar dignitary. 

  • A lack of agitation or disturbance. 

  • The state of being serene; calmness; peacefulness. 

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