bloodhound vs sighthound

bloodhound

noun
  • A large scenthound famed for its ability to follow a scent many days old, over vast distances. This dog is often used as a police dog to track missing people, fleeing suspects, or escaped prisoners. 

  • A detective or other person skilled at finding people or clues. 

sighthound

noun
  • A hound that primarily hunts by sight and speed, instead of by scent and endurance. 

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