slaughterer vs slaughterman

slaughterer

noun
  • A butcher (as a profession or job). 

  • A ritual slaughterer, kosher slaughterer, kosher butcher, shochet / shokhet. 

slaughterman

noun
  • A man employed to slaughter animals in a slaughterhouse. 

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