pietism vs spirituality

pietism

noun
  • A movement in the Lutheran church in the 17th and 18th centuries, calling for a return to practical and devout Christianity. 

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 pietism and spirituality occurred in a corpus of books? (source: Google Ngram Viewer )