demerit vs disrate

demerit

noun
  • A quality of being inadequate; a fault; a disadvantage 

  • A mark given for bad conduct to a person attending an educational institution or serving in the army. 

  • That which one merits or deserves, either of good or ill; desert. 

disrate

verb
  • To lower a rate or rating 

  • To demote a sailor to a lower rank 

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