petty theft vs rip-off

petty theft

noun
  • A theft of property having a value lower than a certain small amount set forth in a statute, and considered to be a less serious class of crime. 

rip-off

noun
  • A theft or robbery. 

  • A copy, especially one that is illegal or inferior. 

  • A bad deal; an unfair or exorbitant price or rate. 

  • A scam. 

How often have the words petty theft and rip-off occurred in a corpus of books? (source: Google Ngram Viewer )