felo de se vs self-immolation

felo de se

noun
  • A crime committed against oneself, in particular suicide 

self-immolation

noun
  • The act of self-sacrificing oneself, in any manner of ways. 

  • The act of setting oneself on fire, especially as a form of protest. 

How often have the words felo de se and self-immolation occurred in a corpus of books? (source: Google Ngram Viewer )