goodbye vs hallo

goodbye

verb
  • To say goodbye; to wish somebody farewell on parting. 

intj
  • Farewell; a formula used to another person or persons when the speaker, writer, or person addressed is departing. 

noun
  • An utterance of goodbye, the wishing of farewell to someone. 

hallo

verb
  • To cry "hallo" (to someone). 

  • To shout, or to call with a loud voice. 

  • To chase while shouting "hallo!" 

  • To shout (something). 

noun
  • The cry "hallo!" 

  • A shout of exultation. 

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