detour vs roundabout route

detour

verb
  • To make a detour. 

  • To direct or send on a detour. 

noun
  • The diversion of the flow of execution for debugging or similar purposes. 

  • A diversion or deviation from one's original route. 

roundabout route

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