bughouse vs mental asylum

bughouse

noun
  • A flea-infested hotel, lodging-house etc. 

  • A prison. 

  • A hospital, especially a lunatic asylum. 

  • A cheap and dirty cinema. 

adj
  • Crazy, insane. 

mental asylum

How often have the words bughouse and mental asylum occurred in a corpus of books? (source: Google Ngram Viewer )