show window vs windowpane

show window

noun
  • A windowed, street-facing compartment in which a selection of a store's merchandise is displayed. 

windowpane

noun
  • A piece of glass filling a window or a section of a window 

  • A gelatin base tab with LSD. 

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