boards vs sports hall

boards

noun
  • Structure around a rink for ice hockey. 

  • A hardcover binding on a book. 

  • Examinations given for entry to college or to qualify for a profession. 

  • A stage (as in a theater). 

sports hall

noun
  • A building, or a room in a building, especially in a school, with facilities to play indoor sports. 

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