execute vs string up

execute

verb
  • To kill, especially as punishment for a capital crime. 

  • To run, usually successfully. 

  • Coordinate term: murder 

  • To carry out; to put into effect. 

  • To perform. 

  • To carry out, to perform an act; to put into effect or cause to become legally binding or valid (as a contract) by so doing. 

  • To start, launch or run 

string up

verb
  • To kill (a person) by hanging, especially to lynch. 

  • To concatenate; to link in a line. 

  • To suspend by means of rope, cord or similar material. 

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