savings bank vs treasure house

savings bank

noun
  • A type of financial institution that focuses on retail banking: savings of private depositors, payments, credits and insurances for individuals or small and medium-sized enterprises. 

treasure house

noun
  • A treasury. 

  • A building where valuable things are stored. 

How often have the words savings bank and treasure house occurred in a corpus of books? (source: Google Ngram Viewer )