employ vs serve notice

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. 

serve notice

verb
  • To warn or announce. 

  • To fire; to terminate one's employment or formal association. 

  • To officially give a legal notice to. 

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