rest home vs roof over one's head

rest 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. 

roof over one's head

noun
  • Somewhere to live; shelter. 

How often have the words rest home and roof over one's head occurred in a corpus of books? (source: Google Ngram Viewer )