prayer vs requesting

prayer

noun
  • An act of praying. 

  • A practice of communicating with one's God, or with some spiritual entity. 

  • The specific words or methods used for praying. 

  • The remotest hope or chance. 

  • A meeting held for the express purpose of praying. 

  • A request; a petition. 

  • One who prays. 

requesting

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