amusement park vs playing field

amusement park

noun
  • A commercially-operated collection of rides, games and other entertainment attractions. 

playing field

noun
  • Any place or context within which competitive activity takes place, such as market competition between companies. 

  • A field on which a game, especially a ball game, is played. 

How often have the words amusement park and playing field occurred in a corpus of books? (source: Google Ngram Viewer )