letter writer vs subeditor

letter writer

noun
  • A correspondent; a writer of letters. 

  • A book containing examples of letters that can be imitated by those who wish to write correspondence. 

  • A person employed to write letters for illiterate people; a person who does this as an occupation. 

subeditor

noun
  • A copy editor at a newspaper or magazine. 

  • An assistant editor, usually in a specific department of a newspaper. 

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