drunk tank vs fish tank

drunk tank

noun
  • A cell where people who have been arrested for public drunkenness are detained until they are sober. 

fish tank

noun
  • A section of a prison for newly arrived inmates. 

  • A container, usually made out of glass or acrylic, specifically designed for holding water and marine life. 

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