immobilization vs passivity

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. 

passivity

noun
  • The state of being passive. 

  • A lack of initiative. 

  • Submissiveness. 

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