cold frame vs patio

cold frame

noun
  • A transparent-roofed enclosure, built low to the ground, used to protect plants from cold weather. 

patio

noun
  • A paved outside area, adjoining a house, used for dining or recreation. 

  • An inner courtyard typical of traditional houses in some regions of Spain. 

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