janitor vs roadsweeper

janitor

noun
  • Someone who looks after the maintenance and cleaning of a public building. 

  • A caretaker or custodian; someone who maintains a school building specifically and may serve other administrative roles. 

  • A doorman. 

  • A moderator for a discussion forum. 

roadsweeper

noun
  • A person employed to sweep streets 

  • A machine used to sweep streets 

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