pilfer vs snarf

pilfer

verb
  • To steal in small quantities, or articles of small value; to practise petty theft. 

snarf

verb
  • To take something by dubious means, but without the connotations of stealing; to take something without regard to etiquette. 

  • To eat or consume greedily. 

  • To slurp (computing slang sense); to load in entirety; to copy as a whole. 

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