room and board vs rooming house

room and board

noun
  • A place of lodging with daily meals, usually provided in return for rent or other considerations. 

rooming house

noun
  • A house which lets out furnished apartments. 

  • A building with small, basic, inexpensive apartments for rent, often without en-suite bathrooms. 

How often have the words room and board and rooming house occurred in a corpus of books? (source: Google Ngram Viewer )