conn vs steersman

conn

noun
  • The duty of directing a ship, usually used with the verb to have or to take and accompanied by the article "the." 

verb
  • To direct a ship; to superintend the steering of (a vessel); to watch the course of (a vessel) and direct the helmsman how to steer (especially through a channel, etc, rather than steer a compass direction). 

steersman

noun
  • One who steers a ship or other vessel; the helmsman. 

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