on offer vs pushover

on offer

prep
  • For sale at a reduced price. 

  • Available to take; at hand; being offered or to be offered. 

pushover

noun
  • Someone who is easily swayed or influenced to change his/her mind or comply. 

  • Something that is easy to do or accomplish; an easy task. 

  • Someone who lets him/herself be picked or bullied on without defending or standing up for him/herself. 

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