drowsiness vs immobilization

drowsiness

noun
  • State of being drowsy. 

immobilization

noun
  • The act or process of preventing a thing from moving. 

  • The process in which organic soil matter is decomposed and absorbed by microorganisms, and thus not available to plants. 

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