immobilization vs stillness

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. 

stillness

noun
  • Habitual silence or quiet; taciturnity. 

  • The quality or state of being still. 

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