lactose vs polysaccharide

lactose

noun
  • The disaccharide sugar of milk and dairy products, C₁₂H₂₂O₁₁, a product of glucose and galactose used as a food and in medicinal compounds. 

polysaccharide

noun
  • A polymer made of many saccharide units linked by glycosidic bonds. 

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