depravation vs downgrade

depravation

noun
  • Detraction; depreciation. 

  • The state of being depraved or degenerated; degeneracy; depravity. 

  • Change for the worse; deterioration; morbid perversion. 

  • The act of depraving, or making anything bad; the act of corrupting. 

downgrade

noun
  • A reduction of a rating, as a financial or credit rating. 

  • A downhill gradient on a road or railway. 

verb
  • to reduce the official estimate of a storm's intensity. 

  • To reduce in complexity, or remove unnecessary parts; to dumb down. 

  • To place lower in position. 

  • To revert software back to an older version. 

  • To disparage. 

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