check in vs occur

check in

verb
  • To send somebody to solitary confinement; to make somebody be admitted to solitary confinement. 

  • To verify a person's information and record their arrival, such as at a hotel, airport, etc. 

  • To integrate new revisions into the public or master version of a file in a version control system. 

  • To visit in order to see how someone is doing. 

  • To announce or record one's own arrival at a hotel, airport etc. 

  • To contact another person in order to keep the other person informed of one's situation. 

  • To return (a book to a library, source code to a repository, etc.). 

  • To enter solitary confinement at one's own request for protection from other prisoners. 

occur

verb
  • To come or be presented to the mind; to suggest itself. 

  • To happen or take place. 

  • To present or offer itself. 

  • To be present or found. 

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