SC vs safety car

SC

noun
  • supercentenarian 

  • simple cubic 

  • subcutaneous injection 

  • stem cell 

  • supercapacitor 

  • supercluster (of galaxies), galaxy superclsuter 

  • superconductor 

adj
  • subcutaneous 

safety car

noun
  • A vehicle employed to lead the competitors in an auto race for the duration of a few laps, with the intention of restricting their speed while a hazard exists on the circuit. 

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