Tower vs graybar hotel

Tower

name
  • The Tower of London, especially seen as a place of imprisonment or punishment. 

  • A habitational surname.; Alternative form of Towers 

noun
  • Denoting the system of weights used by the Saxon and Norman English kings in their minting of coins. 

graybar hotel

name
  • jail, prison 

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