offering vs proffering

offering

noun
  • The act by which something is offered. 

  • Something put forth, bid, proffered or tendered, such as for sale 

  • That which has been offered; a sacrifice. 

  • A contribution given at a religious service. 

  • An oblation or presentation made as a religious act. 

proffering

noun
  • The act by which something is proferred. 

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