depravation vs pejoration

depravation

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

  • Detraction; depreciation. 

  • Change for the worse; deterioration; morbid perversion. 

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

pejoration

noun
  • The act or process of becoming worse; worsening or degeneration. 

  • The process by which a word acquires a more negative meaning over time. 

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