nursing home vs sanatorium

nursing home

noun
  • A place of residence for people who require constant nursing care and have significant deficiencies with activities of daily living, such as the elderly and younger adults with physical disabilities. 

sanatorium

noun
  • An institution that treats chronic diseases, and provides supervised recuperation and convalescence. 

How often have the words nursing home and sanatorium occurred in a corpus of books? (source: Google Ngram Viewer )