discovery vs proofreading

discovery

noun
  • A pre-trial phase in which evidence is gathered. 

  • Something discovered. 

  • Materials revealed to the opposing party during the pre-trial phase in which evidence is gathered. 

  • The discovering of new things. 

proofreading

noun
  • The act or process by which a document is proofread. 

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