pull the trigger vs undertake

pull the trigger

verb
  • To commit to a course of action. 

  • To shoot, kick the ball in hope of scoring a goal. 

  • To fire a gun. 

  • To hit a very powerful shot. 

undertake

verb
  • To commit oneself (to an obligation, activity etc.). 

  • To pass a slower moving vehicle on the curbside rather than on the side closest to oncoming traffic. 

  • To take upon oneself; to start, to embark on (a specific task etc.). 

noun
  • The passing of slower traffic on the curbside rather than on the side closest to oncoming traffic. 

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