lay off vs retain

lay off

verb
  • To place all or part of a bet with another bookmaker in order to reduce risk. 

  • In painting, to apply gentle strokes to smooth a wet coat of paint so as to remove visible roller- or brush-marks, commonly using a dry brush; a similar technique, but using a loaded laying-off brush, may produce a smooth coat of paint when using a roller or the usual brush techniques would leave marks. 

  • To plan out (a navigational course) using a chart. 

  • To cease, quit, stop (doing something). 

  • (of an employer) To dismiss (workers) from employment, e.g. at a time of low business volume or through no fault of the worker, often with a severance package. 

  • To stop bothering, teasing, or pestering someone; to leave (someone) alone. 

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 lay off and retain occurred in a corpus of books? (source: Google Ngram Viewer )