self-immolation vs self-killing

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. 

self-killing

noun
  • The killing of oneself; suicide. 

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