beheading vs decollation

beheading

noun
  • An instance of a person being beheaded. 

decollation

noun
  • The act of beheading someone. 

  • The festival of the Baptist, celebrated on 29 August. 

  • A picture of a decapitation, especially of the head of St John the Baptist on a charger. 

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