meadow vs schoolyard

meadow

noun
  • A field or pasture; a piece of land covered or cultivated with grass, usually intended to be mown for hay. 

  • Low land covered with coarse grass or rank herbage near rivers and in marshy places by the sea. 

schoolyard

noun
  • An open field near a school used for recreation by the students. 

  • The grounds around a school. 

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