boot out vs retain

boot out

verb
  • To fall or slide out of a turn due to excessive lean, which causes the athlete's boot to contact and pivot on the surface and the proper surface contact element to lose contact and traction. 

  • Emphatic synonym of kick out: to remove, to eject, to expel. 

retain

verb
  • To employ by paying a retainer. 

  • To hold back (a pupil) instead of allowing them to advance to the next class or year. 

  • To keep in one's pay or service. 

  • To keep in possession or use. 

  • To hold secure. 

How often have the words boot out and retain occurred in a corpus of books? (source: Google Ngram Viewer )