copy editor vs proofreader

copy editor

noun
  • Someone who corrects printed material and prepares it for typesetting, printing, or online publishing. 

proofreader

noun
  • A person whose occupation is to proofread. 

  • A person who proofreads. 

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