benign vs disease-free

benign

adj
  • Not posing any serious threat to health; not particularly aggressive or recurrent. 

  • Not harmful to the environment. 

  • Kind; gentle; mild. 

  • mild and favorable 

disease-free

adj
  • free of disease, not having, carrying, or suffering from any disease. 

How often have the words benign and disease-free occurred in a corpus of books? (source: Google Ngram Viewer )