employ vs put to work

employ

verb
  • To hire (somebody for work or a job). 

  • To use (somebody for a job, or something for a task). 

  • To make busy. 

noun
  • The state of being an employee; employment. 

put to work

verb
  • Give a job; Force to work (even if it is make-work) 

  • to put to use 

How often have the words employ and put to work occurred in a corpus of books? (source: Google Ngram Viewer )