goof vs japer

goof

noun
  • A foolish and/or silly person; a goofball. 

  • An error made during production which finds its way into the final release. 

  • A mistake or error. 

  • A child molester. 

verb
  • To make a mistake. 

  • To engage in mischief. 

japer

noun
  • One who japes; a joker. 

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