devaluate vs mark down

devaluate

verb
  • To reduce in value. 

mark down

verb
  • To reduce the price of. 

  • To write a memorandum about. 

  • To subtract marks or points from, for an error. 

  • To draw a conclusion about something; to consider something to be a certain way. (Typically used with as.) 

  • To write down. 

How often have the words devaluate and mark down occurred in a corpus of books? (source: Google Ngram Viewer )