du'a' vs spirituality

du'a'

noun
  • private prayer by an individual 

spirituality

noun
  • Appreciation for religious values. 

  • The quality or state of being spiritual. 

  • Concern for that which is unseen and intangible, as opposed to physical or mundane. 

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