recruit vs take on

recruit

verb
  • To supply with new men, as an army; to fill up or make up by enlistment; also, to muster 

  • To enroll or enlist new members or potential employees on behalf of an employer, organization, sports team, the military, etc. 

  • To become an adult or breeding-age member of a population. 

  • To prompt a protein, leucocyte. etc. to intervene in a given region of the body. 

noun
  • A hired worker 

  • A person enlisted for service in the army; a newly enlisted soldier. 

  • A new adult or breeding-age member of a certain population. 

  • A supply of anything wasted or exhausted; a reinforcement. 

take on

verb
  • To acquire, bring in, or introduce. 

  • To assume or take responsibility for. 

  • To (attempt to) dribble round (an opposition player). 

  • To catch on, do well; to become popular. 

  • To obtain the services of (a person) in exchange for remuneration; to give someone a job. 

  • To begin to have or exhibit. 

  • To attempt to fight, compete with, or engage with. 

  • To grieve or be concerned (about something or someone). 

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