city vs grammatical number

city

noun
  • A large amount of something (used after the noun). 

  • A large settlement, bigger than a town; sometimes with a specific legal definition, depending on the place. 

  • A settlement granted special status by royal charter or letters patent; traditionally, a settlement with a cathedral regardless of size. 

  • The central business district; downtown. 

grammatical number

noun
  • the feature of words distinguishing quantities 

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