Kev vs trev

Kev

noun
  • A working-class male. 

name
  • A diminutive of the male given name Kevin. 

trev

noun
  • A farm assistant or other rural worker; an ordinary country bloke. 

  • An urban lower-class youth. 

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