drilling rig vs trickery

drilling rig

noun
  • Used other than figuratively or idiomatically: see drilling, rig. 

  • An oil rig. 

trickery

noun
  • Artifice; the use of one or more stratagems. 

  • The art of dressing up; imposture. 

  • Deception or underhanded behavior. 

  • An instance of deception, underhanded behavior, dressing up, imposture, artifice, etc. 

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