canyon vs glade

canyon

noun
  • A valley, especially a long, narrow, steep valley, cut in rock by a river. 

glade

noun
  • An open passage through a wood; a grassy open or cleared space in a forest. 

  • An everglade. 

  • An open space in the ice on a river or lake. 

  • A bright surface of ice or snow. 

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