SM vs strapping

SM

symbol
  • service mark 

strapping

adj
  • Having a sturdy muscular physique; robust. 

noun
  • A beating with a strap. 

  • A length of narrow material to be used for straps, or straps collectively. 

  • The act of fastening with a strap. 

  • Adhesive plaster for strapping injuries. 

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