exclusion vs initiation

exclusion

noun
  • An item not covered by an insurance policy. 

  • The act of excluding or shutting out; removal from consideration or taking part. 

initiation

noun
  • The first step of transcription or of transduction. 

  • The form or ceremony by which a person is introduced into any society; mode of entrance into an organized body; especially, the rite of admission into a secret society or order. 

  • The act of initiating, or the process of being initiated or introduced 

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