retain vs write off

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. 

write off

verb
  • To treat as a write-off, a total loss, especially something damaged beyond economic repair. 

  • To record (an expenditure) as an expense. 

  • To remove a portion of a debt or an amount of an account owed, counting it as a loss (as a gesture of goodwill for example). 

  • To reduce the book value of (an asset) to zero. 

  • To record a notional expense such as amortization or depreciation. 

  • To assign a low value to (something). 

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