airman vs centurion

airman

noun
  • A pilot of an aircraft. 

  • A naval seaman, especially one in the U.S. Navy, who works on and/or handles aircraft. 

  • A member of an air force. 

  • A person of a rank in the U.S. Air Force above airman basic and below airman first class. 

centurion

noun
  • A pilot in the United States Navy who has performed 100 night landings on an aircraft carrier. 

  • An officer of the ancient Roman army, in command of a century of soldiers. 

  • A player who scores a century. 

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