circus ring vs forestage

circus ring

noun
  • A circular arena in a circus, where the acts are performed. 

forestage

noun
  • The part of a theatre stage in front of the closed curtain. 

  • A service paid by foresters to the king. 

  • A duty or tribute payable to the king's foresters. 

  • A preliminary or developmental stage. 

verb
  • To make prominent; to bring into focus. 

  • To block so that someone or something appears in the forestage. 

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