argonaut vs voyager

argonaut

noun
  • An adventurer on a dangerous but rewarding quest. 

  • Any of several species of shelled octopods of the family Argonautidae (of which only the genus Argonauta is not extinct). 

voyager

noun
  • A person who voyages, traveller, a person who explores new lands and worlds. 

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