buggy vs mentally ill

buggy

adj
  • Crazy; bughouse. 

  • Containing programming errors. 

  • Resembling an insect. 

  • Infested with insects. 

noun
  • A hearse. 

  • A small horse-drawn cart. 

  • A small motor vehicle, such as a dune buggy. 

  • A pushchair; a stroller. 

  • A shopping cart or trolley. 

mentally ill

adj
  • Having a psychological disorder. 

How often have the words buggy and mentally ill occurred in a corpus of books? (source: Google Ngram Viewer )