poster vs wallcovering

poster

noun
  • A picture of a celebrity, an event etc., intended to be attached to a wall. 

  • An advertisement to be posted on a pole, wall etc. to advertise something. 

  • A shot that hits a goalpost, scoring one point. 

  • A shot that hits a goalpost instead of passing into the goal. 

  • A dunk over a defending player. 

  • One who posts a message. 

verb
  • To decorate with posters. 

wallcovering

noun
  • A covering for a wall, such as wallpaper 

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