imbibe vs knock back

imbibe

verb
  • To drink (used frequently of alcoholic beverages). 

  • To take in; absorb. 

knock back

verb
  • To drink an alcoholic beverage swiftly or often. 

  • To stun; to surprise. 

  • To press or knead (dough) so as to remove air bubbles. 

  • To reject; to refuse. 

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