piety vs religiosity

piety

noun
  • A devout act or thought. 

  • Reverence and devotion to God. 

  • A belief that is accepted unthinkingly and with undue reverence. 

  • Similar reverence to one's parents and family or to one's country. 

religiosity

noun
  • The quality of being religious or pious, especially when zealous. 

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