Hansen's disease vs scabies

Hansen's disease

noun
  • The disease leprosy, caused by infection by Mycobacterium leprae. 

scabies

noun
  • An infestation of parasitic mites, Sarcoptes scabiei, causing intense itching caused by the mites burrowing into the skin of humans and other animals. It is easily transmissible from human to human; secondary skin infection may occur. 

How often have the words Hansen's disease and scabies occurred in a corpus of books? (source: Google Ngram Viewer )