inner city vs zoo

inner city

noun
  • The interior, central part of a city, as opposed to the suburbs 

zoo

noun
  • Any place that is wild, crowded, or chaotic. 

  • A zoophile. 

  • A park where live animals are exhibited. 

  • A large and varied collection of something. 

  • The jungle. 

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