knee slapper vs wisecrack

knee slapper

noun
  • A joke, especially one which strikes the listener or reader as particularly humorous. 

wisecrack

noun
  • A witty or sarcastic comment or quip. 

verb
  • To make a sarcastic, flippant, or sardonic comment. 

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