ground plan vs ground-plan

ground plan

noun
  • Hypothetical ancestor of a clade. 

  • Framework or pattern. 

  • Floorplan. 

  • A diagram showing set layout. 

ground-plan

noun
  • Hypothetical ancestor of a clade. 

  • A diagram showing set layout. 

  • Floorplan. 

  • Framework or pattern. 

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