pickpocket vs thief

pickpocket

noun
  • One who steals from the pocket of a passerby, usually by sleight of hand. 

verb
  • To pick pockets; to steal. 

thief

noun
  • One who carries out a theft. 

  • One who steals another person's property, especially by stealth and without using force or violence. 

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