fettering vs repression

fettering

noun
  • The act by which something is fettered or constricted. 

repression

noun
  • The act of repressing; state of being repressed. 

  • The involuntary rejection from consciousness of painful or disagreeable ideas, memories, feelings, or impulses. 

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