bad off vs underprivileged

bad off

adj
  • In unfortunate circumstances, especially having financial difficulty. 

underprivileged

adj
  • Deprived of the opportunities and advantages of others, usually through no fault of one's own. 

noun
  • A deprived person; deprived people (normally used as a plural). 

How often have the words bad off and underprivileged occurred in a corpus of books? (source: Google Ngram Viewer )