diabolic vs iniquitous

diabolic

adj

  • Extremely evil or cruel. 

  • Showing wickedness typical of a devil. 

  • diabolic magic square 

iniquitous

adj

  • Wicked or sinful. 

  • Morally objectionable. 

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