immoral vs retrogressive

immoral

adj
  • Breaching principles of natural law, rectitude, or justice, and so inconsistent with the demands of virtue, purity, or "good morals"; not right, not moral. (Compare unethical, illegal.) 

retrogressive

adj
  • Of or relating to retrogression. 

  • Directed towards the rear or the past; retrograde. 

noun
  • A person of retrogressive views or policies; a backward-looking conservative. 

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