disembark vs embus

disembark

verb
  • To remove from on board a vessel; to put on shore 

  • To go ashore out of a ship or boat; to leave a train or aircraft. 

embus

verb
  • to board a bus 

  • to put (troops) onto a bus 

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