inauguration vs opening ceremony

inauguration

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

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

opening ceremony

noun
  • A ceremony to mark the official opening of a building or event. 

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