japer vs scamp

japer

noun
  • One who japes; a joker. 

scamp

noun
  • A rascal, swindler, or rogue; a ne'er-do-well. 

  • A preliminary design sketch. 

  • A mischievous person, especially a playful, impish youngster. 

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