auction vs auction off

auction

verb
  • To sell at an auction. 

noun
  • The first stage of a deal, in which players bid to determine the final contract. 

  • A public event where goods or property are sold to the highest bidder. 

auction off

verb
  • To sell something at an auction. 

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