fourth estate vs pressman

fourth estate

noun
  • Journalism or journalists considered as a group; the press. 

pressman

noun
  • A journalist or newspaper reporter. 

  • Someone who operates a printing press. 

  • one who presses clothes 

  • one who pressgangs people into naval service 

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