hara-kiri vs self-killing

hara-kiri

noun
  • Suicide or any suicidal action. 

  • Ceremonial suicide by disembowelment, as by slicing open the abdomen with a dagger or knife: formerly practised in Japan by the Samurai when disgraced or sentenced to death. 

  • An act against one's own interests. 

self-killing

noun
  • The killing of oneself; suicide. 

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