mange vs syphilis

mange

noun
  • A skin disease of nonhuman mammals caused by parasitic mites (Sarcoptes spp., Demodecidae spp.). 

syphilis

noun
  • A disease spread via sexual activity, caused by the bacterium Treponema pallidum. 

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