naff off vs screw you

naff off

verb

  • A mild version of fuck off 

screw you

verb

  • Used other than figuratively or idiomatically: see screw, you. 

noun

  • An act of defiance and contempt. 

intj

  • less offensive version of fuck you. 

How often have the words naff off and screw you occurred in a corpus of books? (source: Google Ngram Viewer )