Islamic vs Muslim

Islamic

adj
  • Of, pertaining to, originating in, characteristic of, or deriving from Muslims or Islam. 

noun
  • a malapropism for 'Islamist' 

Muslim

adj
  • Being or relating to a believer of Islam. 

noun
  • A person who is a follower and believer of Islam. 

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