jet bridge vs porch

jet bridge

noun
  • An elevated corridor connecting an airport to a plane, usually enclosed and used for disembarking and embarking passengers and crew. 

porch

noun
  • The platform outside the external hatch of a spacecraft. 

  • A covered entrance to a building, whether taken from the interior, and forming a sort of vestibule within the main wall, or projecting without and with a separate roof. A porch often has chair(s), table(s) and swings. 

  • A portico; a covered walk. 

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