immoral vs non-moral

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.) 

non-moral

adj
  • Not moral; unconnected with morals; having no relation to ethics or morals; not involving ethical or moral considerations. 

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