snore vs z's

snore

noun
  • The act of snoring, and the noise produced. 

  • An extremely boring person or event. 

verb
  • To breathe during sleep with harsh, snorting noises caused by vibration of the soft palate. 

z's

noun
  • Sleep. 

How often have the words snore and z's occurred in a corpus of books? (source: Google Ngram Viewer )