inauguration vs initiation

inauguration

noun
  • The formal beginning or initiation of any movement, enterprise, event etc. 

  • The act of inaugurating, or inducting into office with solemnity; investiture by appropriate ceremonies. 

initiation

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

  • 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. 

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